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

Abstract

Battery, current collector applied thereto, battery pack including the battery, and automobile. The battery of the present invention includes: an electrode assembly that is an electrode assembly in which a first electrode, a second electrode, and a separator film interposed therebetween are wound around a winding axis to define a core portion and an outer peripheral surface, the first electrode including a first non-coated portion in which an active material layer is not coated at a long side end portion in a winding direction and is exposed to an outside of the separator film, at least a portion of the first non-coated portion being used as an electrode tab by itself; a battery case having an open portion on one side, the electrode assembly being accommodated through the open portion; a first current collector including: a support portion disposed at an upper portion of the electrode assembly; a first tab coupling portion extending from the support portion to be coupled to the first non-coated portion; and a first case coupling portion extending from the support portion to be electrically coupled to an inner surface of the battery case; and a case cover sealing the open portion.

Description

Technical Field

[0001] This invention relates to batteries and current collectors used therein, battery packs including the batteries, and automobiles. More specifically, this invention relates to a current collector with a structure that prevents damage to welded joints between the current collector and electrode assembly even when subjected to external impact, and to batteries including the current collector, battery packs including the batteries, and automobiles. Background Technology

[0002] In conventional cylindrical batteries, a structure is typically used where tabs connecting the jelly-roll and external terminals are soldered to foil on the jelly-roll. With this structure, the current path is limited, and the resistance of the jelly-roll itself must be very high.

[0003] Therefore, an attempt was made to reduce the resistance by increasing the number of tabs connecting the winding core and the external terminals. However, it was not possible to reduce the resistance to the desired level and ensure that the current path was limited by simply increasing the number of tabs.

[0004] Therefore, in order to reduce the resistance of the core itself, it is necessary to develop new core structures and current collector structures for such core structures. In particular, such new core and current collector structures are needed in devices such as electric vehicles that require high-output / high-capacity battery packs.

[0005] In addition, there is a need to develop cylindrical batteries with structures that maintain and enhance the bonding force between the current collector and the battery casing, as well as current collector structures for such cylindrical batteries.

[0006] At the same time, it is necessary to develop a cylindrical battery that minimizes the dead corners inside the battery casing while combining the current collector and the battery casing, thereby improving the energy density of the cylindrical battery.

[0007] In recent years, with the application of cylindrical batteries in electric vehicles, the form factor of cylindrical batteries has increased. That is, the diameter and height of cylindrical batteries are larger than those of previous cylindrical batteries with form factors such as 1865 and 2170. The increase in form factor leads to increased energy density, improved safety against thermal runaway, and improved cooling efficiency.

[0008] The energy density of cylindrical batteries can be further increased by minimizing unnecessary space inside the battery casing while increasing shape factors. Therefore, the overall battery structure needs to be designed as a low-resistance structure so that the current collector can also increase the battery capacity while minimizing heat generation during fast charging.

[0009] Furthermore, in the case of battery packs used in electric vehicles, the operating environment is frequently exposed to vibration and shock. Therefore, there is a need to develop a cylindrical battery structure with a low risk of damage to welded joints even under vibration and shock, as well as a current collector structure for such a cylindrical battery. Summary of the Invention

[0010] The problem that the invention aims to solve

[0011] The present invention was developed to solve the problems described above, and its purpose is to provide a current collector suitable for an electrode assembly having a low resistance structure and a battery including the current collector.

[0012] In another aspect, the object of the present invention is to provide a current collector with a structure capable of improving the bonding force at the joint between the current collector and the battery casing, and a battery including the current collector.

[0013] In another aspect, the object of the present invention is to provide a current collector with a structure capable of improving the energy density of a battery and a battery including the current collector.

[0014] In another aspect, the object of the present invention is to provide a current collector and a battery including the current collector with a structure that improves the convenience of the welding process for making electrical connections between the battery casing and the current collector during battery manufacturing, thereby improving productivity.

[0015] In another aspect, the object of the present invention is to provide a current collector and a battery including the current collector such that, even when subjected to vibration and impact, the possibility of damage to the welded parts between the current collector and the electrode assembly and / or the welded parts between the current collector and the battery casing is reduced.

[0016] In another aspect of the invention, the object of the invention is to provide a current collector having a structure that improves the convenience of the welding process for electrically connecting the battery casing and the current collector during battery manufacturing, thereby improving productivity.

[0017] However, the technical problems to be solved by the present invention are not limited to the above-mentioned problems. Those skilled in the art can clearly understand other problems not mentioned herein through the invention description below.

[0018] Methods for solving problems

[0019] To address the aforementioned issues, a battery according to an embodiment of the present invention includes: an electrode assembly that defines a core and an outer peripheral surface by winding a first electrode, a second electrode, and a separator membrane between them around a winding shaft, wherein the first electrode includes a first uncoated portion at its long side end along the winding direction, which is uncoated with an active material layer and exposed to the outside of the separator membrane, and at least a portion of the first uncoated portion itself serves as an electrode tab; a battery casing having an opening on one side through which the electrode assembly is housed; a first current collector including: a support portion disposed on the upper part of the electrode assembly; a first tab joining portion extending from the support portion and joined to the first uncoated portion; a first casing joining portion extending from the support portion and electrically joined to the inner surface of the battery casing; and a casing cover sealing the opening portion.

[0020] The first electrode lug joint and the first outer shell joint are not directly connected, but are indirectly connected through the support portion.

[0021] The battery casing has a rolled edge portion formed at the end adjacent to the open portion and pressed inward.

[0022] The aforementioned first electrode joint has at least one injection hole.

[0023] The aforementioned first outer casing joining portion includes: a first contact portion, which is joined to the rolled edge portion of the aforementioned battery casing; and

[0024] The first connecting portion connects the aforementioned support portion and the aforementioned first contact portion.

[0025] The first connecting portion has a structure that protrudes upward based on an imaginary straight line connecting the two ends of the first connecting portion in the length direction.

[0026] The first connecting portion has a structure that protrudes upwards compared to the rolled edge portion.

[0027] The aforementioned rolled edge portion includes: an upper rolled edge portion, which is located above with the innermost part that is pressed inward as its center; and a lower rolled edge portion, which is located below with the innermost part that is pressed inward as its center.

[0028] The aforementioned upper rolled edge portion and the aforementioned lower rolled edge portion are asymmetrical with reference to an imaginary reference plane that is parallel to the bottom surface of the aforementioned battery casing and passes through the innermost part of the aforementioned rolled edge portion.

[0029] At least one of the first electrode tabs of the first current collector is disposed closer to the lower side than the lower rolled edge portion.

[0030] At least one of the aforementioned upper rolled edge portion and the aforementioned lower rolled edge portion is inclined at a predetermined angle to the lower surface of the aforementioned battery casing.

[0031] The first contact portion is disposed on the inclined upper surface of the rolled edge portion.

[0032] At least one of the aforementioned upper rolled edge portion and the aforementioned lower rolled edge portion is parallel to the lower surface of the aforementioned battery casing in at least a portion of the region.

[0033] The first contact portion is disposed on the flat upper surface of the rolled edge portion.

[0034] The first contact portion is welded to the upper surface of the rolled edge portion.

[0035] The aforementioned first contact portion is welded to a flat area formed on the aforementioned upper rolled edge portion.

[0036] The first contact portion has an arc shape that extends in the circumferential direction along at least a portion of the rolled edge of the battery casing.

[0037] The first contact portion has an arc shape that extends in opposite directions along the circumferential direction from the intersection of the first connecting portion and the first contact portion on the rolled edge portion.

[0038] In the aforementioned battery, the pressing depth of the rolled edge is set as PD, and the minimum value of the radius of curvature of the rolled edge is set as R1. min Set the minimum weld width to W. bead，min Let R2 be the minimum radius of curvature in the boundary region between the rolled edge and the inner side of the battery casing. min When, the following equation is satisfied.

[0039] PD≥R1, min +R2, min +W bead，min

[0040] The pressing depth of the above-mentioned rolled edge is 0.2 to 10 mm.

[0041] In the aforementioned battery, the pressing depth of the rolled edge is set to PD, and the maximum value of the pressing depth is set to PD. max Let the shortest distance from the end of the first contact portion to the vertical line passing through the innermost part of the rolled edge portion, i.e., the overlap length, be OV, and let the minimum value of the radius of curvature of the rolled edge portion be R1. min Set the minimum weld width to W. bead，min Let R2 be the minimum radius of curvature in the boundary region between the rolled edge and the inner side of the battery casing.min When, the following equation is satisfied.

[0042] (R1, min +W bead，min ) / PD max ≤OV / PD≤(PD max -R2, min ) / PD max

[0043] The welding area between the first contact portion and the rolled edge portion is narrower than the flat upper surface of the rolled edge portion.

[0044] In the aforementioned battery, the pressing depth of the rolled edge is set to PD, and the maximum value of the pressing depth is set to PD. max Let W be the distance from the innermost part of the rolled edge to the center of the weld bead located on the outermost contour in the radial direction; let OV be the shortest distance, i.e., the overlap length, from the end of the first contact part to the vertical line passing through the innermost part of the rolled edge; and let OV be the minimum value of OV. min Set the maximum value of OV to OV. max Set the minimum weld width to W. bead，min When, the following equation is satisfied.

[0045] (OV min -0.5*W bead，min ) / PD max ≤W / PD≤(OV max -0.5*W bead，min ) / PD max

[0046] In the battery described above, when the minimum value of the distance from the innermost part of the rolled edge to the center of the weld bead located at the outermost contour in the radial direction is set to W1, and the distance from the innermost part of the rolled edge to the center of the weld bead located at the outermost contour in the radial direction when the overlap length is OV is set to W, the following formula is satisfied.

[0047] W1 = R1 + 0.5 * W bead，min

[0048] W = OV - 0.5 * W bead，min

[0049] The aforementioned rolled edge portion has a flat section parallel to the lower surface of the aforementioned battery casing in at least a portion of the region. When the overlap length is OV and the radius of curvature of the aforementioned rolled edge portion is R1, the length of the aforementioned flat section of the aforementioned rolled edge portion that contacts the aforementioned first current collector is OV–R1.

[0050] The width and length of the welding pattern formed between the rolled edge and the first contact portion in the radial direction is W. bead，min Above and below OV–R1.

[0051] The ratio of the width and length of the welded pattern in the radial direction to the length of the flat section is in the range of 10% to 40%.

[0052] The first connecting portion has at least one first curved portion, which changes its extension direction at least once.

[0053] The aforementioned first curved portion is positioned closer to the top than an imaginary plane that passes through the center of an imaginary straight line connecting one end of the aforementioned first contact portion and one end of the aforementioned first tab joint portion and is parallel to the bottom surface of the aforementioned battery casing.

[0054] The aforementioned first curved portion is bent at an obtuse angle so that it does not overlap with each other when viewed along the axis in the length direction of the aforementioned battery casing.

[0055] The boundary between the first contact portion and the first connecting portion is bent into an obtuse angle.

[0056] The first connecting portion has a shape in which its inclination gradually decreases as it approaches the rolled edge portion.

[0057] The angle between the first electrode lug joint and the first connecting part is between 0 and 90 degrees.

[0058] The first connecting portion supports the outer casing cover.

[0059] The aforementioned first electrode joint and the aforementioned first contact portion are located at substantially the same height.

[0060] The first contact portion has a flat surface that engages with the upper surface of the rolled edge portion facing the open portion.

[0061] The first current collector described above has a current collector hole formed at its center.

[0062] The aforementioned current collector hole is located at a position corresponding to the winding hole formed in the center of the aforementioned electrode assembly.

[0063] The diameter of the current collector hole is greater than or equal to the diameter of the winding hole provided in the core of the electrode assembly.

[0064] The first current collector also includes a second housing connection portion, which extends from the end of one of the plurality of first tab connections and is connected to the inner side of the battery housing.

[0065] The aforementioned second housing assembly includes: a second contact portion which is attached to the inner side of the aforementioned battery housing; and a second connecting portion which connects the end of one of the plurality of aforementioned first tab assemblies to the aforementioned second contact portion.

[0066] The second contact portion has a shape in which at least a portion extends along the inner circumferential surface of the battery casing.

[0067] The second connecting portion has at least one second bend, which changes its extension direction at least once.

[0068] The distance from the center of the first current collector to the end of the first tab joint is substantially the same as or shorter than the distance from the center of the winding hole of the electrode assembly to the innermost part of the rolled edge.

[0069] The upper surface of the aforementioned rolled edge portion has a flat portion.

[0070] There is at least one weld bead formed between the rolled edge and the first contact portion, and at least one of the weld beads forms a weld pattern in a straight line shape extending along the circumferential direction.

[0071] There is at least one weld bead formed between the rolled edge and the first contact portion, and at least one of the weld beads forms an arc-shaped weld pattern extending along the circumferential direction.

[0072] The weld bead formed between the rolled edge and the first contact portion forms a welding pattern, and the welding pattern has a line shape formed by connecting spot welds.

[0073] Multiple weld beads are formed between the rolled edge portion and the first contact portion.

[0074] The second electrode further includes a second uncoated portion at its long side end along the winding direction, which is not coated with an active material layer and is exposed to the outside of the separation membrane. At least a portion of the second uncoated portion is itself used as an electrode tab. In this case, the battery further includes a terminal that penetrates the battery casing from the opposite side of the opening and is electrically connected to the second uncoated portion.

[0075] The battery further includes a second current collector located between the electrode assembly and the terminal. The second current collector includes: a second tab connection portion connected to the second uncoated portion; and a terminal connection portion connected to the terminal.

[0076] The aforementioned terminal joint covers the winding hole of the aforementioned electrode assembly.

[0077] The outer diameter of the second collector is larger than the outer diameter of the first collector.

[0078] The aforementioned second electrode lug is joined to the joint surface formed by bending the aforementioned second uncoated portion.

[0079] The battery casing has a crimping portion formed on the upper part of the rolled edge portion and extends and bends in a manner that surrounds the outer edge of the casing cover.

[0080] The first outer shell joint is pressed and fixed by the pressing part.

[0081] The battery also includes a sealing gasket disposed within the crimping portion and between the battery casing and the casing cover.

[0082] The first contact portion is located between the rolled edge portion and the sealing gasket.

[0083] The first contact portion is fixed by bending the crimping portion.

[0084] The thickness of the sealing gasket in the area that contacts the first contact portion is greater than its thickness in the area that does not contact the first contact portion.

[0085] The compression ratio of the sealing gasket in the area that contacts the first contact portion is greater than that in the area that does not contact the first contact portion.

[0086] The compression ratio of the aforementioned sealing gasket in the area in contact with the aforementioned first contact portion is substantially the same as the compression ratio in the area not in contact with the aforementioned first contact portion.

[0087] The thickness of the sealing gasket changes in each region along the circumferential direction on the aforementioned rolled edge.

[0088] The thickness of the aforementioned sealing gasket alternately increases and decreases along the circumferential direction on the aforementioned rolled edge portion.

[0089] Along the circumferential direction on the aforementioned rolled edge, the compression ratio of the aforementioned gasket changes in each region.

[0090] The first outer shell joint is elastically biased on the rolled edge portion.

[0091] The connection portion of the first contact portion and the first connecting portion matches the inner surface of the rolled edge portion.

[0092] At least a portion of the first uncoated portion includes a plurality of segmented pieces divided along the winding direction of the electrode assembly, the plurality of segmented pieces being bent along the radial direction of the electrode assembly to form a bent surface.

[0093] The aforementioned multiple segmented pieces are overlapped in multiple layers to form a bent surface. The bent surface includes a range where the number of overlapping layers of the segmented pieces increases from the outer periphery of the electrode assembly to the core side, up to a maximum value, and a range where the number of overlapping layers is uniform from the radius where the number of overlapping layers reaches its maximum value to the radius where the innermost segmented piece exists.

[0094] The first tab joint is joined to the bending surface in such a way that it overlaps with the uniform interval of the stacked layers.

[0095] The number of overlapping layers in the above-mentioned uniform layer number interval is 10 or more.

[0096] The first tab joint is welded to the bending surface, and the welding area of ​​the tab joint overlaps with the uniform stacking interval by at least 50% along the radial direction of the electrode assembly.

[0097] The first uncoated portion and the first tab joint portion are joined together by welding along the radial direction of the electrode assembly.

[0098] The first tab joint is welded to the first uncoated part in a manner parallel to the lower surface of the battery casing.

[0099] The weld bead formed between the first uncoated portion and the first tab joint portion forms a straight weld pattern that extends along the radial direction of the electrode assembly.

[0100] A weld bead formed between the first uncoated portion and the first tab joint portion forms a welding pattern, and the welding pattern has a line shape formed by spot welding.

[0101] The width of the weld bead formed between the first uncoated portion and the first tab joint portion is 0.1 mm or more.

[0102] The aforementioned first electrode tab joint and the aforementioned first outer shell joint are formed in multiple forms, and the multiple aforementioned first electrode tab joints and first outer shell joints are arranged radially, cross-shaped or combined with the center portion of the aforementioned first current collector as a reference.

[0103] Multiple of the aforementioned first outer shell joints are respectively disposed between adjacent first tab joints.

[0104] The aforementioned first outer shell joint is formed in multiple parts, and the first contact portions of each of the multiple aforementioned first outer shell joints are connected to each other to form a whole.

[0105] The outermost part of the first connecting portion is separated from the innermost part of the rolled edge portion by a predetermined interval.

[0106] The angle between the first contact portion and the first connecting portion forms an acute angle through the first curved portion.

[0107] It has multiple of the above-mentioned injection holes.

[0108] The plurality of injection holes are arranged symmetrically about the center of the first electrode joint in the width direction.

[0109] Weld lines are formed between the injection holes arranged symmetrically on the left and right sides for joining the first tab joint and the first uncoated part.

[0110] The aforementioned first electrode lug joint is formed such that its width at a position separated by a predetermined distance from the end of the first electrode lug joint in the length direction of the connection portion of the first electrode lug joint and the support portion is greater than the width at the connection portion of the first electrode lug joint and the support portion.

[0111] The aforementioned injection hole is formed at a predetermined distance from the end of the connection portion along the length direction toward the first electrode joint portion.

[0112] At least a portion of the area where the injection hole is formed includes the area where the width increases at a predetermined distance from the end of the first electrode joint to the end of the first electrode joint, compared to the width at the connection between the first electrode joint and the support.

[0113] The end of the first tab joint in the length direction has an arc shape corresponding to the inner circumferential surface of the battery casing.

[0114] The extension direction of the welding pattern formed between the first uncoated portion and the first tab joint portion is perpendicular to the extension direction of the welding pattern formed between the rolled edge portion and the first contact portion.

[0115] In the radial direction, the innermost part of the rolled edge is positioned closer to the inside than the end part of the crimped part.

[0116] The aforementioned sealing gasket surrounds the aforementioned outer casing cover, and the radial length of the portion of the aforementioned sealing gasket that covers the lower surface of the aforementioned outer casing cover is shorter than the radial length of the portion of the aforementioned sealing gasket that covers the upper surface of the aforementioned outer casing cover.

[0117] In the battery described above, when the total length in the radial direction of the first tab joint is set as T, the outer diameter of the electrode assembly is set as JR, and the height of the segment plate disposed on the outermost contour of the electrode assembly is set as F, the following formula is satisfied.

[0118] JR–2*F≤T <JR

[0119] The ratio of the area of ​​the first current collector that does not contact the upper surface of the electrode assembly to the area of ​​a circle with the outer diameter of the electrode assembly is 30% or more and less than 100%.

[0120] The ratio of the area of ​​the first current collector that does not contact the electrode assembly to the area of ​​a circle with the outer diameter of the electrode assembly is 60% or more and less than 100%.

[0121] The diameter of the current collector hole is smaller than the diameter of the winding hole provided in the core of the electrode assembly.

[0122] When the diameter of the winding hole is set to R3, the diameter of the current collector hole is 0.5*R3 or more but less than R3.

[0123] When the diameter of the winding hole is set to R3, the diameter of the current collector hole is 0.7*R3 or more but less than R3.

[0124] The ratio of the shape factor obtained by dividing the diameter of the battery by its height is greater than 0.4.

[0125] In the aforementioned battery, the resistance measured between the anode and cathode is less than 4 mΩ.

[0126] Additionally, a battery according to an embodiment of the present invention includes: an electrode assembly that defines a core and an outer peripheral surface by winding a first electrode, a second electrode, and a separator membrane between them around a winding axis, wherein the first electrode has a first uncoated portion at its long side end along the winding direction, which is not coated with an active material layer and is exposed to the outside of the separator membrane, and at least a portion of the first uncoated portion itself serves as an electrode tab; a battery casing having an opening on one side and housing the electrode assembly through the opening; and a current collector electrically coupled to the first uncoated portion and the inner surface of the battery casing, wherein the current collector includes a first portion in contact with the inner surface of the battery casing and a second portion coupled to the first uncoated portion, and when the central region of the first portion is projected onto the plane of the second portion, the central region of the first portion and the second portion are separated along the circumferential direction of the electrode assembly.

[0127] The battery also includes a sealing gasket located between the opening of the battery casing and the current collector.

[0128] The first part is located between the inner surface of the battery casing and the sealing gasket, and the first part and the second part are located on different planes in the winding axis direction of the electrode assembly.

[0129] In addition, to address the aforementioned housing issue, one embodiment of the present invention provides a current collector for electrical connection between the battery electrode assembly and the battery casing. The current collector includes: a support portion disposed on the upper part of the electrode assembly; a plurality of tab coupling portions extending from the support portion and coupled to a first uncoated portion of the electrode assembly; and a first casing coupling portion extending from the support portion and located between adjacent tab coupling portions and electrically coupled to the rolled edge portion of the battery casing.

[0130] In a current collector according to one embodiment of the present invention, the aforementioned tab connection portion and the aforementioned first housing connection portion are not directly connected, but are indirectly connected through the aforementioned support portion.

[0131] The aforementioned tab joint has at least one injection hole.

[0132] The aforementioned first housing assembly includes: a first contact portion which is attached to the inner side of the aforementioned battery housing; and a first connecting portion which connects the aforementioned support portion and the aforementioned first contact portion.

[0133] The first connecting portion has at least one first curved portion, which changes its extension direction at least once.

[0134] The aforementioned current collector has a current collector hole formed at its center.

[0135] The current collector further includes a second housing connection portion, which extends from the end of one of the plurality of tab connections and is connected to the inner side of the battery housing.

[0136] The aforementioned second housing assembly includes: a second contact portion which is attached to the inner side of the aforementioned battery housing; and a second connecting portion which connects the end of one of the plurality of tab assemblies to the aforementioned contact portion.

[0137] It has multiple first outer shell joints, and the first contact portions of each of the multiple first outer shell joints are connected to each other to form a whole.

[0138] The angle between the first contact portion and the connecting portion forms an acute angle through the first curved portion.

[0139] It has multiple of the above-mentioned injection holes.

[0140] The aforementioned injection holes are arranged symmetrically on the left and right sides with reference to the center of the aforementioned tab joint in the width direction.

[0141] Compared to the width at the connection between the aforementioned tab joint and the aforementioned support portion, the width of the aforementioned tab joint at a position separated by a predetermined distance from the end of the aforementioned connection portion in the length direction toward the aforementioned tab joint is greater.

[0142] The aforementioned injection hole is located at a predetermined distance from the end of the connection portion along the length direction toward the tab joint portion.

[0143] At least a portion of the area where the injection hole is formed includes the area where the width increases at a position that is a predetermined distance away from the end of the electrode joint compared to the width at the connection between the tab joint and the support.

[0144] The end of the aforementioned tab joint in the longitudinal direction has an arc shape corresponding to the inner circumferential surface of the aforementioned battery casing.

[0145] In addition, a battery pack according to one embodiment of the present invention includes a plurality of batteries as described above in one embodiment of the present invention.

[0146] Multiple of the aforementioned batteries are arranged in a predetermined number of columns, with the terminals of each battery and the outer surface of the bottom of the battery casing facing upwards.

[0147] The battery pack of the present invention includes: a plurality of buses that connect a plurality of batteries in series and in parallel, each bus being disposed on the upper part of an adjacent battery, each bus including: a main body extending between adjacent terminals; a plurality of first bus terminals extending toward one side of the main body and electrically coupled to the electrode terminals of the battery located on the said side; and a plurality of second bus terminals extending toward the other side of the main body and electrically coupled to the outer surface of the bottom of the battery casing of the battery located on the said other side.

[0148] An embodiment of the automobile of the present invention includes a battery pack as described above in one embodiment of the present invention.

[0149] Invention Effects

[0150] According to the present invention, resistance can be greatly reduced when electrically connecting the electrode assembly to the battery casing.

[0151] In another aspect, according to the present invention, the bonding force at the joint between the current collector and the battery casing can be improved.

[0152] In another aspect, according to the present invention, the energy density of the battery can be increased.

[0153] In another aspect, according to the present invention, the convenience of the welding process for electrically connecting the battery casing and the current collector can be improved during battery manufacturing, thereby improving productivity.

[0154] In another aspect, according to the present invention, even if vibration and impact are applied during battery use, the possibility of damage to the welded joints between the current collector and the electrode assembly and / or the welded joints between the current collector and the battery casing can be reduced.

[0155] Furthermore, according to the present invention, the convenience of the welding process for electrically connecting the battery casing to the current collector can be improved during battery manufacturing, thereby improving productivity.

[0156] However, the effects of the present invention are not limited to those described above, and those skilled in the art can clearly understand other technical effects not mentioned herein through the following description of the invention. Attached Figure Description

[0157] The accompanying drawings illustrate preferred embodiments of the invention and, together with the detailed description below, further aid in understanding the technical concept of the invention. Therefore, the invention is not limited to the matters shown in the drawings.

[0158] Figure 1 This is a cross-sectional view showing the internal structure of a cylindrical battery according to an embodiment of the present invention.

[0159] Figure 2 This is a diagram illustrating a current collector (first current collector) according to an embodiment of the present invention.

[0160] Figures 3 to 5 This is a diagram illustrating various exemplary configurations of the first connection portion of a current collector (first current collector) according to an embodiment of the present invention.

[0161] Figure 6 and Figure 7 This is a diagram showing the shape of the first connection portion, which varies depending on the height of each electrode assembly.

[0162] Figure 8 This is a diagram illustrating a current collector (first current collector) according to another embodiment of the present invention.

[0163] Figure 9 This is a diagram illustrating a current collector (first current collector) according to yet another embodiment of the present invention.

[0164] Figure 10 It is shown Figure 9 A diagram illustrating the morphology of the second connection portion of the current collector (first current collector).

[0165] Figure 11 and Figure 12 This is a diagram showing a current collector (first current collector) of the present invention in a form different from that described and illustrated in the above embodiments.

[0166] Figure 13 This shows the application. Figure 12 The diagram shows the internal structure of the cylindrical battery with the current collector (first current collector).

[0167] Figure 14 This is a top view showing the combined configuration of the current collector (first current collector) and the battery casing of the present invention.

[0168] Figure 15 This is an enlarged view of the upper part of the electrode assembly of the present invention.

[0169] Figure 16 It is Figure 15 An enlarged view of the upper part of the uncoated section.

[0170] Figure 17 This diagram illustrates the welding process for the current collector (first current collector).

[0171] Figure 18 This diagram illustrates the beading process for the battery casing.

[0172] Figure 19 This diagram illustrates the crimping process for the battery casing.

[0173] Figure 20 This diagram illustrates the sizing process for the battery casing.

[0174] Figure 21 This diagram illustrates the shape change of the current collector (first current collector) after the fine pressing process, based on the shape of the current collector before the fine pressing process.

[0175] Figure 22 and Figure 23 This diagram illustrates the shape of a current collector (first current collector) configured in a way that maintains the welded area even after the precision pressing process.

[0176] Figure 24 This diagram illustrates the position, length, and width of the weld bead in the welding area between the contact portion and the rolled edge portion of the current collector (first current collector) formed in this invention.

[0177] Figure 25 This is a diagram illustrating one embodiment of the current collector (second current collector) applied to the present invention.

[0178] Figure 26 It is shown that... Figure 25 The diagram shows different embodiments of the current collector (second current collector).

[0179] Figure 27This is a top view illustrating an electrode structure of a preferred embodiment of the present invention.

[0180] Figure 28 This is a cross-sectional view of an electrode assembly in which the uncoated segment structure of the first electrode of an embodiment of the present invention is applied to the second electrode by cutting along the length direction Z.

[0181] Figure 29 This is a cross-sectional view of an electrode assembly whose uncoated portion is bent along the length direction Z, according to an embodiment of the present invention.

[0182] Figure 30 This is a perspective view of an electrode assembly with its uncoated portion bent according to an embodiment of the present invention.

[0183] Figure 31 This is a top top view showing how multiple cylindrical batteries of an embodiment of the present invention are connected in series and parallel using a bus.

[0184] Figure 32 This is a diagram illustrating a schematic structure of a battery pack including a cylindrical battery according to an embodiment of the present invention.

[0185] Figure 33 This is a diagram illustrating a schematic structure of a car including a battery pack according to an embodiment of the present invention.

[0186] (Symbol Explanation)

[0187] 5: Automobile; 3: Battery pack; 2: Packaging shell; 1: Cylindrical battery; 10: Electrode assembly; 11: First uncoated part; 12: Second uncoated part; H1: Winding hole; 20: Battery shell; 20a: Outer surface of the closing part; T1: First electrode terminal; 21: Rolled edge part; 22: Press-fit part; 30: Current collector (first current collector); H2: Current collector hole; 31: Support part; 32: Tab connection part (first tab connection part); H3: Liquid injection hole; 33: First shell connection part; 3 3a: First contact portion; 33b: First connecting portion; 34: Second housing joint portion; 34a: Second contact portion; 34b: Second connecting portion; 40: Housing cover; 41: Vent portion; G1: Sealing gasket; 50: Terminal; T2: Second electrode terminal; G2: Insulating gasket; 60: Current collector (second current collector); 61: Edge portion; 62: Electrode joint portion (second electrode joint portion); 63: Terminal joint portion; 64: Bridging portion; 64a: Tapered portion; N: Current cutting-off portion; 70: Insulator. Detailed Implementation

[0188] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings. Prior to this, the terms or words used in this specification and claims should not be limited to their ordinary or dictionary meanings. The inventors, based on the principle that the concepts of terms can be appropriately defined in order to best illustrate their invention, interpret them as meanings and concepts consistent with the technical ideas of the present invention. Therefore, the embodiments described in this specification and the structures shown in the accompanying drawings are only some of the most preferred embodiments of the present invention and do not represent all the technical ideas of the present invention. Therefore, it should be understood at the time of this application that various equivalents and modifications may exist that can replace these.

[0189] Furthermore, to aid in understanding the invention, the accompanying drawings are not shown to scale, but rather with some of the constituent elements enlarged. Additionally, in different embodiments, the same reference numerals are used for the same constituent elements.

[0190] When referring to two objects as 'identical,' it means 'substantially identical.' Therefore, substantially identical includes cases where deviations are considered low in the field, such as within 5%. Furthermore, uniformity of a parameter within a region means uniformity from an average perspective.

[0191] First, refer to Figure 1 An embodiment of the present invention provides a cylindrical battery 1 comprising an electrode assembly 10, a battery casing 20, a current collector (first current collector) 30, a casing cover 40, and terminals 50. The cylindrical battery 1 may further include a sealing gasket G1 and / or an insulating gasket G2 and / or a current collector (second current collector) 60 and / or an insulator 70. The present invention is not limited to the shape of the battery and can also be applied to batteries of other shapes, such as prismatic batteries.

[0192] The electrode assembly 10 described above includes a first uncoated portion 11 and a second uncoated portion 12. More specifically, the electrode assembly 10 has a structure in which a first electrode and a second electrode, with a separation membrane between them, are wound around a winding shaft to define the core and outer peripheral surface. That is, the electrode assembly 10 applied to the present invention can be a core-type electrode assembly. In this case, a separation membrane is additionally provided on the outer peripheral surface of the electrode assembly 10 to achieve insulation with the battery casing 20. The electrode assembly 10 described above can have a winding structure known in the art.

[0193] The aforementioned first electrode includes a first electrode current collector and a first electrode active material coated on one or both sides of the first electrode current collector. In the width direction of the aforementioned first electrode (and... Figure 1The cylindrical battery 1 shown in the diagram has an uncoated portion (within the height direction) on one side end, where the first electrode active material is not coated. That is, the first electrode has an uncoated portion at its long side end along the winding direction, where the active material is not coated and it protrudes to the outside of the separation membrane. Hereinafter, this uncoated portion, which serves as the first electrode tab, will be referred to as the first uncoated portion 11. The first uncoated portion 11 is provided in the height direction (parallel to the height direction) of the electrode assembly 10 housed within the battery casing 20. Figure 1 The upper part of the cylindrical battery 1 shown in the figure (parallel to the height direction). That is, the first electrode has a first uncoated portion at its long side end that is not coated with an active material layer and is exposed to the outside of the separation membrane. At least a portion of the first uncoated portion itself is used as an electrode tab. The first uncoated portion 11 is, for example, a cathode tab.

[0194] On the other hand, at least a portion of the first uncoated portion 11 includes a plurality of segmented pieces divided along the winding direction of the electrode assembly 10. In this case, the plurality of segmented pieces ( Figure 30 The symbol 11a) bends along the radial direction of the electrode assembly 10.

[0195] Reference Figure 1 , Figure 15 and Figure 16 The multiple segments of the bent first uncoated portion 11 overlap to form a bending surface (joint surface) 102. In this case, the tab joint portion (first tab joint portion) 32 of the current collector (first current collector) 30 (described later) is joined to the bending surface 102. The tab joint portion 32 is joined to the region where the multiple segments overlap to form multiple layers. The bending surface 102 includes a layer number increasing range from the outer periphery of the electrode assembly 10 towards the core side to a maximum value, and a layer number uniform range from the radius where the number of overlapping layers reaches its maximum value to the radius where the innermost segment exists.

[0196] In this case, with the aforementioned tab joint (first tab joint 32) positioned on the bent surface 102 of the first uncoated portion 11, welding is performed on a certain area. That is, the aforementioned tab joint 32 is bonded to a region formed by multiple overlapping segments of the first uncoated portion 11. For example, the aforementioned tab joint 32 is bonded to the bent surface 102 to overlap with a region of uniform layer number. (Refer to...) Figure 16 The welding of the aforementioned tab joint 322 and the first uncoated portion 11 is performed in the region of the bending surface 102 of the first uncoated portion 11 where the number of overlapping layers of the first uncoated portion 11 is approximately 10 or more. By adjusting the length of the first uncoated portion 11, the ratio in the radial direction of the region where the number of overlapping layers is 10 or more is designed to be approximately 25% or more, based on the radius of the electrode assembly 10 excluding the core.

[0197] The tab joint portion (first tab joint portion) 32 of the aforementioned current collector (first current collector) 30 is bonded to the bending surface 102 to overlap with the aforementioned uniform layer number interval. Preferably, the tab joint portion 32 is welded to the bending surface 102, and the welding area of ​​the tab joint portion 32 overlaps with the uniform layer number interval by at least 50% along the radial direction of the electrode assembly 10. Preferably, the number of overlapping layers in the aforementioned uniform layer number interval is approximately 10 or more.

[0198] When welding the current collector 30 to the bent surface 102 of the first uncoated portion 11, it is preferable to increase the laser output to ensure sufficient welding strength. However, when the laser output is increased, the laser can penetrate the overlapping area of ​​the first uncoated portion 11 and reach the interior of the electrode assembly 10, thereby damaging the separation membrane, active material layer, etc. Therefore, to prevent laser penetration, it is preferable to increase the number of overlapping layers of the first uncoated portion 11 to a certain level or higher. Increasing the number of overlapping layers of the first uncoated portion 11 requires increasing the height of the segmented sheet. However, when the height of the segmented sheet is increased, ripples may occur in the first uncoated portion 11 during the manufacturing process of the first electrode current collector. Therefore, it is preferable to adjust the height of the segmented sheet to an appropriate level.

[0199] As described above, based on the radius of the electrode assembly, the length ratio in the radial direction of the segmented sheets with an overlap of 10 or more layers of uncoated portions is designed to be 25% or more. When laser welding is performed on the area of ​​the segmented sheets of uncoated portions with an overlap of 10 or more layers and the current collector 30, even if the laser output is increased, the overlapping parts of the uncoated portions can fully shield the laser, thereby preventing the separation membrane, active material layer, etc. from being damaged by the laser.

[0200] Preferably, the laser output is appropriately adjusted within the range of approximately 250W to 320W, or within approximately 40% to 90% of the maximum laser output specification, but the invention is not limited thereto. When the laser output meets the above-mentioned numerical range, the welding strength can be sufficiently increased. As an example, a welding strength of 2 kgf / cm² is used. 2 The above is more preferably increased to 4 kgf / cm. 2 The above. The preferred welding strength is set at 8 kgf / cm². 2 Hereinafter, a more preferred setting is 6 kgf / cm². 2 The following is the tensile force per unit area of ​​current collector 30 when the weld strength begins to separate from the bent surface area (kgf / cm²). 2 The definition is as follows: After welding the current collector, a tensile force is applied to it and gradually increased. As the tensile force increases, the uncoated portion begins to separate from the weld interface. At this point, the weld strength is the value obtained by dividing the tensile force applied to the current collector by the area of ​​the current collector.

[0201] Figure 16 This is a partial cross-sectional view showing the first uncoated portion 11 of the first electrode current collector, divided into multiple segmented pieces, in an electrode assembly having a cylindrical battery with a shape factor of 4680, a radius of 22 mm, and a core radius of 4 mm. The first portion is bent from the outer periphery towards the core, resulting in more than 10 overlapping bent surface areas. The electrode assembly area without segmented pieces and the core area are not separately illustrated in the figure. Regarding the height of the segmented pieces, starting from 3 mm, the height of the segmented pieces increases by 1 mm for every 1 mm increase in the radius of the electrode assembly. Furthermore, once the lengths shown in the figure—6 mm, 7 mm, or 8 mm—are reached, the height of the segmented pieces remains substantially the same.

[0202] Reference Figure 16 As the number of overlapping layers of the first uncoated portion 11 gradually increases from the outer periphery to the core side, the longer the length of the first uncoated portion 11, the greater the maximum value of the number of overlapping layers.

[0203] As an example, when the length of the first uncoated portion 11 is 8 mm, the number of overlapping layers of the first uncoated portion 11, which is divided into multiple segments, increases to 18 sheets from the outer peripheral surface of the electrode assembly to the 7 mm interval. In the 8 mm interval on the core side, the number of overlapping layers of the first uncoated portion 11 remains at the maximum value of 18 sheets, while decreasing by 1-2 sheets in the radius interval adjacent to the core. The height of the segmented sheets increases progressively from 3 mm to 8 mm in the radius range of 7 mm to 12 mm. In this invention, as... Figure 16 As shown, the uniform stacking interval is defined as the radius from the region where the number of overlapping layers reaches its maximum value to the region where the innermost segment is located. Therefore, the ratio of the uniform stacking interval of the segment of the first uncoated portion 11 with more than 10 overlapping layers to the radius of the electrode assembly excluding the core (4 mm) is 44.4% (8 / 18).

[0204] As another example, when the length of the first uncoated portion 11 is 7 mm, the number of overlapping layers of the first uncoated portion 11, which is divided into multiple segments, increases to 15 sheets from the outer peripheral surface of the electrode assembly to the 6 mm range. In the 9 mm range on the core side, the number of overlapping layers of the first uncoated portion 11 remains at the maximum value of 15 sheets, while decreasing by 1-2 sheets in the radius range adjacent to the core. Regarding the height of the segments, it increases in stages from 3 mm to 7 mm in the radius range of 7 mm to 11 mm. Therefore, the ratio of the uniform number of overlapping layers of the segments of the first uncoated portion 11 with more than 10 sheets to the radius of the electrode assembly excluding the core (4 mm) is 50% (9 / 18).

[0205] As another example, when the length of the first uncoated portion 11 is 6 mm, the number of overlapping layers of the first uncoated portion 11, which is divided into multiple segments, increases to 12 sheets from the outer peripheral surface of the electrode assembly to the 5 mm interval. In the 10 mm interval on the core side, the number of overlapping layers of the first uncoated portion 11 remains unchanged at the maximum value of 12 sheets, while decreasing by 1-2 sheets in the radius interval adjacent to the core. The height of the segments increases from 3 mm to 6 mm in the radius interval of 7 mm to 10 mm. Therefore, the ratio of the uniform number of overlapping layers of the segments of the first uncoated portion 11 with more than 10 sheets to the radius of the electrode assembly excluding the core (4 mm) is 55.6% (10 / 18).

[0206] As can be seen from the embodiments, regarding the length of the interval where the number of overlapping layers increases, the length of the first uncoated portion 11 increases from 5 mm to 7 mm. Specifically, based on the radius of the electrode assembly other than the core, the ratio of the uniform interval with 10 or more overlapping layers satisfies the condition of 25% or more.

[0207] In this invention, the uniformity interval of the number of layers is increased or decreased based on the radius of the core, the minimum and maximum values ​​of the segment heights within the variable height interval of the segment pieces, and the increase in the height of the segment pieces in the radial direction of the electrode assembly. Therefore, it is readily apparent to those skilled in the art that this ratio is designed to be 25% or higher by adjusting the factors influencing the ratio of the uniformity interval of the number of layers. As an example, within the variable height interval of the segment pieces, when both the minimum and maximum values ​​of the segment heights are increased simultaneously, the number of layers increases, and the ratio of the uniformity interval of the number of layers decreases to the 25% level.

[0208] The uniform stack-up region is the area where current collectors can be welded. Therefore, when the ratio of the uniform stack-up region is adjusted to 25% or more, the weld strength of the current collector can be ensured to be within the preferred range, which is also advantageous in terms of the resistance of the weld interface.

[0209] The aforementioned 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. In the width direction of the aforementioned second electrode (and... Figure 1The cylindrical battery 1 shown in the figure has an uncoated portion (without active material coating) at one end along its height direction (parallel to the direction of height). That is, the second electrode has an uncoated portion at its long side end along the winding direction, where the active material is not coated and it protrudes to the outside of the separation membrane. Hereinafter, this uncoated portion, which serves as the second electrode tab, will be referred to as the second uncoated portion 12. The second uncoated portion 12 is located at the lower part of the electrode assembly 10 housed within the battery casing 20 in the height direction. That is, the second electrode has a second uncoated portion at its long side end, where the active material layer is not coated and it protrudes to the outside of the separation membrane, and at least a portion of the second uncoated portion itself serves as an electrode tab. The second uncoated portion 12 is, for example, an anode tab.

[0210] On the other hand, at least a portion of the second uncoated portion 12 includes a plurality of segmented pieces divided along the winding direction of the electrode assembly 10. In this case, the plurality of segmented pieces are bent along the radial direction of the electrode assembly 10.

[0211] Reference Figure 1 , Figure 15 and Figure 16 The multiple segments of the bent second uncoated portion 12 are overlapped to form a bending surface (joint surface) 102. In this case, the tab joint portion (second tab joint portion) 62 of the current collector (second current collector) 60, described later, is joined to the bending surface 102. The tab joint portion 62 is joined to the region where the multiple segments are overlapped to form multiple layers. The bending surface 102 includes a layer number increasing range from the outer periphery of the electrode assembly 10 towards the core side to a maximum value, and a layer number uniform range from the radius where the number of overlapping layers reaches the maximum value to the radius where the innermost segment exists.

[0212] The tab joint portion (second tab joint portion) 62 of the aforementioned current collector (second current collector) 60 is bonded to the bending surface to overlap with the aforementioned uniform layer number interval. Preferably, the tab joint portion 62 is welded to the bending surface 102, and the welding area of ​​the tab joint portion 62 overlaps with the uniform layer number interval by at least 50% along the radial direction of the electrode assembly 10. Preferably, the number of overlapping layers in the aforementioned uniform layer number interval is approximately 10 or more.

[0213] When welding the first current collector 30 and / or the second current collector 60 onto the generally flat mating surface 102 formed by bending the first uncoated portion 11 and / or the second uncoated portion 12, it is preferable to increase the laser output to ensure sufficient welding strength. When the laser output is increased, the laser may penetrate the overlapping area of ​​the first uncoated portion 11 and / or the second uncoated portion 12 and reach the interior of the electrode assembly 10, damaging the separation membrane, active material layer, etc. Therefore, to prevent laser penetration, it is preferable to increase the number of overlapping layers of the first uncoated portion 11 and / or the second uncoated portion 12 to a certain level or higher. To increase the number of overlapping layers of the first uncoated portion 11 and / or the second uncoated portion 12, it is necessary to increase the height of the segmented sheet. However, when the height of the segmented sheet is increased, ripples may occur in the first uncoated portion 11 and / or the second uncoated portion 12 during the manufacturing process of the electrode plate. Therefore, it is preferable to adjust the height of the segmented sheet to an appropriate level.

[0214] As described above, relative to the radius of the electrode assembly 10, the length in the radial direction of the section where the number of overlapping layers of the first uncoated portion 11 and / or the second uncoated portion 12 is 10 or more is designed to be approximately 25% or more. When welding is performed in the above-mentioned welding target area, even if the laser output increases, the overlapping portion of the first uncoated portion 11 and / or the second uncoated portion 12 will fully shield the laser, thus preventing damage to the separation membrane, active material layer, etc. caused by the laser.

[0215] In this invention, any active material known in the art can be used for both the anodic active material coated on the anode plate and the cathode active material coated on the cathode plate.

[0216] As an example, the anolyte active material includes materials with 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; stoichiometric coefficients x, y, and z are selected in a manner that keeps the compound electrically neutral) represent alkali metal compounds.

[0217] As another example, the anolyte active material is the alkali metal compound xLiM disclosed in US 6,677,082, US 6,680,143, etc. 1 O2-(1-x)Li2M 2 O3(M 1 Includes at least one element having an average oxidation state of 3; M2 comprising at least one element having an average oxidation state of 4; 0≤x≤1).

[0218] As another example, the anode active material is represented by 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 comprises at least one element selected from the group consisting of Ti, Si, Mn, Co, Fe, V, Cr, Mo, Ni, Nd, Al, Mg and Al; M 2 comprises at least one element selected from the group consisting of Ti, Si, Mn, Co, Fe, V, Cr, Mo, Ni, Nd, Al, Mg, Al, As, Sb, Si, Ge, V and S; M 3 comprises a halogen element optionally including F; 0<a≤2, 0≤x≤1, 0≤y<1, 0≤z<1; the stoichiometric coefficients a, x, y and z are selected in a manner that maintains the compound electrically neutral) or lithium metal phosphate represented by Li3M2(PO4)3 [M comprises at least one element selected from the group consisting of Ti, Si, Mn, Fe, Co, V, Cr, Mo, Ni, Al, Mg and Al].

[0219] Preferably, the anode active material comprises primary particles and / or secondary particles formed by agglomeration of primary particles.

[0220] As an example, carbon materials, lithium metal or lithium metal compounds, silicon or silicon compounds, tin or tin compounds, etc. can be used as the cathode active material. Metal oxides such as TiO2 and SnO2 with a potential less than 2V can also be used as the cathode active material. As the carbon material, low-crystallinity carbon, high-crystallinity carbon, etc. can be used.

[0221] As the separation membrane, a porous polymer membrane can be used, for example, a porous polymer membrane made of polyolefin polymers such as ethylene homopolymer, propylene homopolymer, ethylene / butene copolymer, ethylene / hexene copolymer, ethylene / methyl acrylate copolymer can be used alone or by laminating a plurality of said membranes. As another example, a conventional porous nonwoven fabric, for example, a nonwoven fabric composed of high-melting-point glass fibers, polyethylene terephthalate fibers, etc., can be used as the separation membrane.

[0222] The separation membrane comprises a coating of inorganic particles on at least one surface. Alternatively, the separation membrane itself may also be composed of a coating of inorganic particles. The particles constituting the coating may have a structure in which they are bonded to the binder in a manner that creates interstitial volumes between adjacent particles.

[0223] The inorganic particles are composed of inorganic materials with a dielectric constant of 5 or higher. As a non-limiting example, the aforementioned inorganic particles include those selected from Pb(Zr,Ti)O3 (PZT), Pb... 1-x La x Zr 1-y Ti y O3(PLZT), PB(Mg3Nb) 2 / 3 It refers to at least one substance in the group consisting of O3-PbTiO3 (PMN-PT), BaTiO3, hafniaHfO2, SrTiO3, TiO2, Al2O3, ZrO2, SnO2, CeO2, MgO, CaO, ZnO and Y2O3.

[0224] Electrolytes are those with A + B - Salts with this structure. Here, A + Including Li + Na + K + Such alkali metal cations, or ions formed by combinations thereof. And B - Including the choice of F - Cl - ,Br - I - NO3 - N(CN)2 - BF4 - ClO4 - AlO4 - AlCl4 - PF6 - SbF6 - AsF6 - BF2C2O4 - BC4O8 - (CF3)2PF4 - (CF3)3PF3 - (CF3)4PF2 - (CF3)5PF - (CF3)6P - CF3SO3 - C4F9SO3 - CF3CF2SO3 -(CF3SO2)2N - (FSO2)2N - CF3CF2(CF3)2CO - (CF3SO2)2CH - (SF5)3C - (CF3SO2)3C - CF3(CF2)7SO3 - CF3CO2 - CH3CO2, SCN - and (CF3CF2SO2)2N - Any one or more anions in the group.

[0225] Electrolytes can also be dissolved in organic solvents for use. Suitable organic solvents include propylene carbonate (PC), ethylene carbonate (EC), diethyl carbonate (DEC), dimethyl carbonate (DMC), dipropyl carbonate (DPC), dimethyl sulfoxide, acetonitrile, dimethoxyethane, diethoxyethane, tetrahydrofuran, N-methyl-2-pyrrolidone (NMP), ethyl methyl carbonate (EMC), γ-butyrolactone, or mixtures thereof.

[0226] Reference Figure 1 The aforementioned battery casing 20 is a generally cylindrical housing with an opening on one side, and is made of a conductive metal material. The side surface of the aforementioned battery casing 20 and the lower surface located on the opposite side of the opening (as shown in the image) Figure 1 The lower surface (based on the reference surface) is typically formed as a single unit. That is, the upper end of the battery casing 20 in the height direction is typically open, while the lower end is typically closed. The lower surface of the battery casing 20 is generally flat. The battery casing 20 houses the electrode assembly 10 through an opening formed on one side in the height direction (parallel to the Z-axis). The battery casing 20 also houses the electrolyte through the aforementioned opening.

[0227] The battery casing 20 has a rolled edge portion 21 formed at an end adjacent to the open portion provided at the upper end of the battery casing 20. The battery casing 20 also has a crimping portion 22 formed on the rolled edge portion 21. The rolled edge portion 21 has a shape in which the outer peripheral edge of the battery casing 20 is pressed into a predetermined depth.

[0228] The pressing depth of the aforementioned rolled edge portion 21 is, for example, approximately 0.2 to 10 mm. Regarding the minimum pressing depth PD of the aforementioned rolled edge portion 21, the radius of curvature R1 of the rolled edge portion 21 and the width W of the weld bead should be taken into account. bead The radius of curvature R2 in the boundary region between the rolled edge 21 and the inner side surface of the battery casing 20. For example, refer to Figure 24 In order to enable welding, additional space is required on top of the radius of curvature R1 of the rolled edge 21 and the radius of curvature R2 in the boundary region between the rolled edge 21 and the inner surface of the battery casing 20. This is because if the indentation depth PD is R1 + R2, there is no flat section F on the rolled edge 21. Therefore, in order to enable welding, the additionally required space should be the minimum width W of the aforementioned weld bead BD. bead，min Therefore, the minimum indentation depth PD satisfies the following relationship.

[0229] PD≥R1, min +R2, min +W bead，min

[0230] For example, R1, min and R2, min The minimum values ​​are approximately 0.05 mm, W bead，min It is approximately 0.1 mm. In this case, the minimum indentation depth (PD) is approximately 0.2 mm or more.

[0231] On the other hand, the maximum value of the pressing depth PD of the rolled edge 21 varies depending on the material and thickness of the battery casing 20. For example, when the battery casing 20 is made of steel and its maximum thickness is approximately 1 mm, the maximum value of the pressing depth PD of the rolled edge 21 is approximately 10 mm. Therefore, for example, the pressing depth PD of the rolled edge 21 has a value between approximately 0.2 and 10 mm.

[0232] The aforementioned rolled edge 21 is formed on the upper part of the electrode assembly 10. The inner diameter of the battery casing 20 in the region where the rolled edge 21 is formed is smaller than the diameter of the electrode assembly 10. The rolled edge 21 includes an upper rolled edge centered on the innermost portion of the battery casing 20 that is pressed in, and a lower rolled edge centered on the innermost portion that is pressed in, and located below it. At least one tab connection portion 32 of the current collector 30, described later, is provided closer to the lower side than the lower rolled edge.

[0233] At least one of the aforementioned upper and lower rolled edges has a shape that is inclined at a predetermined angle to the lower surface of the battery casing 20. In this case, the first contact portion 33a of the current collector (first current collector) 30, described later, is disposed on the inclined upper surface of the upper rolled edge portion of the rolled edge portion 21.

[0234] In contrast, at least one of the aforementioned upper and lower rolled edges has a shape that is substantially parallel to the lower surface of the battery casing 20 in at least a portion of its area. In this case, the first contact portion 33a of the current collector 30, described later, is disposed on the substantially flat upper surface of the upper rolled edge. The aforementioned first contact portion 33a has a flat surface that engages with the upper surface of the rolled edge portion 21 facing the opening side of the battery casing 20.

[0235] The aforementioned rolled edge 21 provides a support surface for the housing cover 40 to be disposed. Additionally, the aforementioned rolled edge 21 provides a support surface for at least a portion of the peripheral edge of the current collector 30 (described later) to be disposed and joined. That is, at least a portion of the peripheral edge of the current collector 30 and / or the peripheral edge of the housing cover 40 of the present invention are disposed on the upper surface of the aforementioned upper rolled edge. In order to stably support at least a portion of the peripheral edge of the current collector 30 and / or the peripheral edge of the housing cover 40, the upper surface of the aforementioned upper rolled edge has a shape that extends 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. Such a rolled edge 21 can be omitted, and at least a portion of the peripheral edge of the current collector 30 can be directly attached to the flat sidewall of the battery housing 20.

[0236] Reference Figure 1 and Figure 20 The aforementioned rolled edge portion 21 includes an upper rolled edge portion and a lower rolled edge portion located at the top and bottom, respectively, based on the innermost portion located along the pressing direction. The upper and lower rolled edge portions have asymmetrical shapes. Specifically, the upper and lower rolled edge portions have asymmetrical shapes based on an imaginary reference plane that passes through the innermost portion of the rolled edge portion and is parallel to the bottom surface of the battery casing 20. This asymmetrical shape is formed during a sizing process, where the battery casing 20 is compressed along its height direction (parallel to the Z-axis). The sizing process is a process of pressing the battery casing 20 according to the winding axis direction of the electrode assembly 10 to make the height of the cylindrical battery 1 conform to the design shape factors.

[0237] The aforementioned upper rolled edge portion has a flat portion that is substantially parallel to the closing portion of the battery casing 20. Conversely, due to its asymmetrical shape, the lower rolled edge portion has a form that slopes downward at least partially in the direction toward the innermost portion. As a result, the aforementioned lower rolled edge portion presses against the upper part of the electrode assembly 10 for fixation. The aforementioned rolled edge portion 21 allows the electrode assembly 10, which has a size that substantially corresponds to the inner diameter of the battery casing 20, to be concealed through the opening formed at the upper end of the battery casing 20, and functions as a support portion for mounting the casing cover 40. The aforementioned upper rolled edge portion serves as a support portion for fixing the casing cover 40 and the first contact portion 33a of the current collector (first current collector) 30, the sealing gasket G1, etc.

[0238] The aforementioned crimping portion 22 is formed on the upper part of the rolled edge portion 21. The crimping portion 22 has a shape that extends and curves to surround the outer periphery of the outer casing cover 40 disposed on the upper part of the rolled edge portion 21. With this shape of the crimping portion 22, the outer casing cover 40 is fixed to the rolled edge portion 21. Of course, the crimping portion 22 can be omitted, and the outer casing cover 40 can be fixed by covering the opening of the battery casing 20 using other fixing structures. The innermost portion of the rolled edge portion 21 is disposed closer to the inner side along the radial direction of the electrode assembly 10 than the end portion of the crimping portion 22. For example, referring to… Figure 1 Compared to the innermost portion of the rolled edge 21, the end portion of the pressing portion 22 is positioned further outward in the radial direction. This structure allows the rolled edge 21 to remain relatively flat even after the precision pressing process. However, if, for example, the innermost portion of the rolled edge 21 is positioned further outward in the radial direction than the end portion of the pressing portion 22, the radial length of the upper surface of the pressing portion 22 will be longer than the radial length of the rolled edge 21. This results in a wider area of ​​the upper surface of the pressing portion 22, the part subjected to pressure during the precision pressing process, thus preventing the rolled edge 21 from becoming flat after the precision pressing process.

[0239] Below, refer to Figures 1 to 5 The current collector (first current collector) 30 of one embodiment of the present invention will be specifically described.

[0240] First, refer to Figure 1 and Figure 2 In one embodiment of the present invention, the current collector 30 is housed inside the battery casing 20, electrically connected to the electrode assembly 10, and electrically connected to the battery casing 20. That is, the current collector 30 electrically connects the electrode assembly 10 and the battery casing 20.

[0241] The current collector 30 includes a support portion 31 located on one side of the electrode assembly 10, a plurality of tab joints (first tab joints) 32 bonded to the first uncoated portion 11, and a plurality of first housing joints 33 extending from the support portion 31 and bonded to the inner side of the battery casing 20. The tab joints 32 and the first housing joints 33 are indirectly connected through the support portion 31 and are not directly connected to each other. Therefore, when an external impact is applied to the cylindrical battery 1 of the present invention, the possibility of damage to the joint between the current collector 30 and the electrode assembly 10 and the joint between the current collector 30 and the battery casing 20 is minimized. At least one of the tab joints 32 and / or first housing joints 33 is provided. At least one tab joint 32 and at least one first housing joint 33 are arranged with reference to the center portion of the current collector 30 in, for example, a generally radial, cross-shaped, or combination thereof configuration. On another side, a plurality of first housing joints 33 are respectively arranged between adjacent tab joints 32.

[0242] The aforementioned support portion 31 and multiple tab coupling portions 32 are disposed on the upper part of the electrode assembly 10. The tab coupling portions 32 are coupled to the first uncoated portion 11 of the electrode assembly 10. The tab coupling portions 32 are welded to the first uncoated portion 11, for example, along the radial direction of the electrode assembly 10. The tab coupling portions 32 are welded to the first uncoated portion 11, for example, in a state substantially parallel to the lower surface of the battery casing 20. The weld bead formed between the first uncoated portion 11 and the tab coupling portions 32 forms a generally straight welding pattern, for example, extending along the radial direction of the electrode assembly 10. The welding pattern, for example, has a line shape formed by spot welding. The welding pattern includes one or more patterns extending along the radial direction of the electrode assembly 10.

[0243] On the other hand, the aforementioned tab connection portion 32 and the aforementioned support portion 31 are combined with the first uncoated portion 11. The aforementioned tab connection portion 32 and the first uncoated portion 11 are combined by welding. When the battery casing 20 forms a rolled edge portion 21, the aforementioned support portion 31 and tab connection portion 32 are arranged closer to the lower part than the rolled edge portion 21.

[0244] The aforementioned support portion 31 includes a current collector hole H2, which is formed at a position corresponding to the take-up hole H1 formed approximately at the center of the electrode assembly 10. The interconnected take-up hole H1 and current collector hole H2 serve as channels for inserting a welding rod or irradiating a laser beam for welding between the terminal 50 and the current collector (second current collector) 60 (described later) or between the terminal 50 and a lead tap (not shown). The current collector hole H2 has a diameter substantially the same as or larger than the take-up hole H1 of the electrode assembly 10, so as not to obstruct the take-up hole H1 formed in the core of the electrode assembly 10. If the diameter of the current collector hole H2 is too small than the diameter of the take-up hole H1, the hole formed in the take-up hole H1 will be obstructed, resulting in decreased injection performance and insufficient space for inserting a welding device or irradiating a laser.

[0245] Unlike the above embodiments, according to another embodiment of the present invention, the diameter of the current collector hole H2 may be smaller than that of the winding hole H1. In this case, for example, when the diameter of the winding hole H1 is set to R3, the diameter of the current collector hole H2 is approximately 0.5*R3 or more and less than R3, preferably approximately 0.7*R3 or more and less than R3. Under normal circumstances, when venting occurs, gas is discharged from the winding center portion of the electrode assembly 10 and, under strong pressure, causes the separation film or uncoated portion located on the winding center side to be exposed from the upper surface of the electrode assembly 10. At this time, when the diameter of the current collector hole H2 is smaller than the diameter of the hole provided in the core portion of the electrode assembly 10, it is possible to prevent the separation film or uncoated portion located on the winding center side from detaching from the electrode assembly 10. However, if the diameter of the current collector hole H2 is too small, the electrolyte injection will decrease, and it is necessary to ensure space for welding the second current collector 60 and the terminal 50. Therefore, the diameter of the current collector hole H2 is preferably about 0.5*R3 or more, and more preferably 0.7*R3 or more.

[0246] The aforementioned plurality of tab joints 32 have a generally radial shape extending from the support portion 31 of the current collector 30 toward the sidewall of the battery casing 20. The plurality of tab joints 32 are arranged spaced apart from each other along the edge of the support portion 31. On the other hand, in order to ensure bonding strength and reduce resistance by increasing the bonding area between the current collector 30 and the electrode assembly 10, the tab joints 32 and the support portion 31 are bonded to the first uncoated portion 11. At least a portion of the first uncoated portion 11 is shaped such that its end is bent in a manner generally parallel to the tab joint 32. In this case, the bend is, for example, formed toward the winding center C side of the electrode assembly 10. Thus, with the end of the first uncoated portion 11 formed and bonded to the tab joint 32 in a state parallel to it, the bonding area is increased, resulting in improved bonding strength and reduced resistance; furthermore, the overall height of the electrode assembly 10 is minimized, resulting in increased energy density. On the other hand, the bent ends of the first uncoated portion 11 overlap in multiple layers. In the case of multiple layers of the first uncoated portion 11, as described above, the tab bonding portion 32 of the current collector 30 is bonded to the bonding surface 102 (see reference) formed by bending and overlapping multiple layers of the first uncoated portion 11. Figure 15 and Figure 16 The same applies to the above situation.

[0247] The aforementioned plurality of first housing joint portions 33 have a shape that extends radially from the support portion 31 of the current collector 30 toward the sidewall of the battery casing 20. The plurality of first housing joint portions 33 are arranged spaced apart from each other along the edge of the support portion 31. At least one first housing joint portion 33 is present between adjacent tab joint portions 32. The plurality of first housing joint portions 33 are joined to, for example, a rolled edge portion 21 on the inner side surface of the battery casing 20. Specifically, the first housing joint portions 33 are joined to the upper surface of the rolled edge portion 21. In the cylindrical battery 1 of the present invention, when such a structure is applied, the first housing joint portions 33 are naturally placed onto the rolled edge portion 21 by the process of housing the electrode assembly 10, in which the current collector 30 is joined, inside the battery casing 20. Therefore, the welding process between the battery casing 20 and the current collector 30 can be performed smoothly. Regarding the welding used to join the battery casing 20 and the current collector 30, laser welding, ultrasonic welding, or spot welding are used, for example. By welding the first housing joint portion 33 onto the rolled edge portion 21, multiple current paths are formed, limiting the resistance level to approximately 4 mΩ (milliohms) or less, suitable for fast charging. This resistance can be 0.5 mΩ or more and 4 mΩ or less, preferably 1 mΩ or more and 4 mΩ or less. Furthermore, the upper surface of the rolled edge portion 21 extends in a direction approximately parallel to the lower surface of the battery housing 20, i.e., approximately perpendicular to the sidewall of the battery housing 20. The first housing joint portion 33 also extends in the same direction, i.e., the radial direction and the circumferential direction, thereby ensuring stable contact between the first housing joint portion 33 and the rolled edge portion 21. Moreover, with the first housing joint portion 33 stably contacting the rolled edge portion 21, welding between the two components can be performed smoothly, thereby improving the bonding strength between the two components and minimizing the increase in resistance at the joint.

[0248] Next, refer to Figures 3 to 7 The aforementioned first outer casing joint 33 includes a first contact portion 33a that is attached to the inner side of the battery casing 20 and a first connecting portion 33b that connects the support portion 31 and the first contact portion 33a.

[0249] The first contact portion 33a is bonded to the inner side surface of the battery casing 20. When the battery casing 20 has a rolled edge portion 21, as described above, the first contact portion 33a is bonded to the rolled edge portion 21. In this case, as described above, to achieve stable contact and bonding, both the rolled edge portion 21 and the first contact portion 33a have a shape that extends in a direction approximately parallel to the lower surface of the battery casing 20, i.e., approximately perpendicular to the sidewall of the battery casing 20. Furthermore, although not shown, the connection portion between the first contact portion 33a and the first connecting portion 33b matches the inner side surface of the rolled edge portion 21. That is, the shape of the connection portion between the first contact portion 33a and the first connecting portion 33b is matched with the shape of the rolled edge portion 21 at the corresponding position. In this case, when the first casing bonding portion 33 is bonded to the rolled edge portion 21, the bonding force between the first casing bonding portion 33 and the rolled edge portion 21 is increased, and with the increased contact area, the effect of reducing resistance can be enhanced. On the other hand, the outermost part of the first connecting portion 33b is separated from the innermost part of the rolled edge portion 21 by a predetermined interval.

[0250] The aforementioned first connecting portion 33b includes at least one first curved portion B1 whose extension direction changes at least once between the support portion 31 and the first contact portion 33a. The aforementioned first connecting portion 33b includes a spring-like structure or a telescopic structure that can contract and extend within a certain range. With such a structure of the first connecting portion 33b, even if the electrode assemblies 10 are highly dispersed within a certain range, the first contact portion 33a is tightly pressed against the rolled edge portion 21 during the process of housing the electrode assembly 10 with the current collector 30 into the battery casing 20.

[0251] For example, preferably, the vertical distance D between the first contact portion 33a and the support portion 31, in a state where no external force is applied to the current collector 30 and no deformation occurs, is substantially the same as or smaller than the vertical distance between the upper surface of the rolled edge portion 21 and the support portion 31 when the electrode assembly 10 with the current collector 30 attached is placed inside the battery casing 20. That is, the first casing joint portion 33 is elastically biased on the rolled edge portion 21. More specifically, the first casing joint portion 33 is attached to the rolled edge portion 21 in a state where it stores elastic energy that deforms in the direction of decreasing linear distance from one end to the other end in the length direction of the first connection portion 33b. When the first connection portion 33b satisfies such a condition, when the electrode assembly 10 with the current collector 30 attached is placed inside the battery casing 20, the first contact portion 33a naturally adheres tightly to the rolled edge portion 21.

[0252] Furthermore, through the retractable and extendable structure of this first connecting portion 33b, when using the cylindrical battery 1 (refer to...) Figure 1 During the process, vibrations and / or impacts may occur, causing the electrode assembly 10 to move up and down. This can also alleviate the impact caused by the movement of the electrode assembly 10 within a certain range. That is, through the retractable and stretchable structure of the first connecting part 33b, a buffering effect can be achieved so that the impact is not transmitted to the joint between the first contact part 33a and the battery casing 20 and the joint between the tab joint 32 and the first uncoated part 11 (see reference). Figures 1 to 5 ).

[0253] On the other hand, the first contact portion 33a is welded to the upper surface of the rolled edge portion 21 (the upper surface of the upper rolled edge portion). Furthermore, the first contact portion 33a is welded to a flat area on the upper surface of the rolled edge portion 21. The welding area between the first contact portion 33a and the rolled edge portion 21 is narrower than the flat upper surface of the rolled edge portion 21. When the first bend portion B1 is provided, the angle between the first contact portion 33a and the first connecting portion 33b becomes an acute angle through the first bend portion B1.

[0254] Next, refer to Figure 8 The image shows a current collector 30 according to another embodiment of the present invention. The current collector 30 of this other embodiment of the present invention is similar to the current collector 30 described above (see reference 30). Figure 2 Compared to the illustrative current collector, the only difference is in the shape of the first contact portion 33a; all other aspects are substantially the same as the structure of the current collector 30 described above.

[0255] Reference Figure 1 and Figure 8 The first contact portion 33a has an arc shape extending circumferentially along the rolled edge 21 of the battery casing 20 at least in part. In this case, to maximize the contact area, the sum of the circumferential extension lengths of the first contact portions 33a of each of the plurality of first casing joints 33 of the current collector 30 is substantially the same as or slightly shorter than the inner circumference of the battery casing 20. On another side, the first contact portion 33a has an arc shape extending circumferentially in opposite directions on the rolled edge 21 from the intersection of the connecting portion 33b and the contact portion 33a.

[0256] Next, refer to Figure 1 , Figure 9 and Figure 10 This illustrates a current collector 30 according to yet another embodiment of the present invention. The current collector 30 of this further embodiment of the present invention is similar to the current collector 30 of the above embodiments (see reference 1). Figure 2 and Figure 8Compared to the illustrative current collector, the only difference is that it also has a second housing joint 34. Other than that, it is the same as the current collector 30 described above (see [reference]). Figure 9 The structures are essentially the same.

[0257] The aforementioned second housing connection portion 34 extends from the end of the tab connection portion 32 and is connected to the inner surface of the battery housing 20. Such a second housing connection portion 34 is provided at the end of at least one of the plurality of tab connections 32. The aforementioned second housing connection portion 34 includes a second contact portion 34a connected to the inner surface of the battery housing 20 and a second connecting portion 34b connecting the support portion 31, the end of the tab connection portion 32, and the second contact portion 34a.

[0258] The second contact portion 34a is attached to the inner side surface of the battery casing 20. When the battery casing 20 has a rolled edge portion 21, the second contact portion 34a is attached to the rolled edge portion 21 in the same way as the first contact portion 33a. In this case, as described above, for stable contact and attachment, both the rolled edge portion 21 and the second contact portion 34a are shaped to extend in a direction substantially parallel to the lower surface of the battery casing 20, i.e., substantially perpendicular to the sidewall of the battery casing 20.

[0259] On the other hand, although not illustrated, such as Figure 8 The first contact portion 33a shown in the figure is shaped such that at least a portion of the second contact portion 34a also extends in the circumferential direction along the rolled edge 21 of the battery casing 20. In this case, in order to maximize the contact area between the current collector 30 and the battery casing 20, the sum of the circumferential extension lengths of the first contact portions 33a of each of the plurality of first casing joint portions 33 and the sum of the circumferential extension lengths of the second contact portions 34a of each of the plurality of second casing joint portions 34 in the current collector 30 is substantially the same as or slightly shorter than the inner circumference of the battery casing 20.

[0260] Similar to the first connecting portion 33b described above, the second connecting portion 34b includes at least one second bend B2, the second bend B2 changing its extension direction at least once between the tab joint portion 32 and the second contact portion 34a. Through the formation of the second bend B2, the second connecting portion 34b has a retractable and stretchable structure, thereby providing advantages in the assembly process of the cylindrical battery 1 and a cushioning effect, as described above.

[0261] In the accompanying drawings of this invention, only the case with one of the aforementioned second curved portions B2 is illustrated, but the invention is not limited thereto, and is consistent with the above-described references. Figure 4 and Figure 5Similarly, the first connecting portion 33b, which is illustrated illustratively, may also have multiple second curved portions B2.

[0262] Reference Figure 11 The illustration shows a current collector 30 with a different configuration than the one described above. (Refer to...) Figure 1 and Figure 11 The current collector (first current collector) 30 of the present invention includes at least one injection hole H3. The injection hole H3 is provided, for example, at a tab connection portion 32. In the case of having multiple tab connections 32, the injection hole H3 is provided at least one tab connection portion 32. The injection hole H3 is provided, for example, on one or both sides of at least one weld bead W formed on the tab connection portion 32. (Refer to...) Figure 1 and Figure 11 In manufacturing a cylindrical battery 1 according to an embodiment of the present invention, after the assembly including the electrode assembly 10 and the current collector (first current collector) 30 is housed inside the battery casing 20, electrolyte is injected. At this time, the injectability is improved through the above-mentioned injection hole H3.

[0263] A plurality of injection holes H3 are provided in a tab joint 32. The plurality of injection holes H3 are arranged approximately symmetrically about the center of the tab joint 32 in the width direction. Thus, a weld bead W for bonding the tab joint 32 and the first uncoated portion 11 is formed between the approximately symmetrically arranged injection holes H3.

[0264] In the aforementioned tab connection portion 32, the width at a predetermined distance from the end of the tab connection portion along its length is greater than the width at the connection point between the tab connection portion 32 and the support portion 31. At least a portion of the area where the injection hole H3 is formed includes the area where the width at a predetermined distance from the end of the tab connection portion 32, compared to the width at the connection point between the tab connection portion 32 and the support portion 31, is increased. Furthermore, the end of the tab connection portion 32 along its length has a generally arcuate shape to correspond to the inner circumference of the battery casing 20.

[0265] Reference Figure 12 and Figure 13 The first connecting portion 33b of the first outer shell joint 33 and / or the second connecting portion 34b of the second outer shell joint 34 of the present invention have a single-bend shape, and are oriented towards and Figure 3 and Figure 10 The illustrations show different bending configurations. Specifically, the second bending portion B2 formed on the first bending portion B1 and / or the second bending portion 34b of the first connecting portion 33b has a bending direction toward the cylindrical battery 1 (see reference). Figure 1The first connecting portion 33b and / or the second connecting portion 34b are shaped to protrude towards the center of the battery casing 20. The bending direction of these first connecting portions 33b and / or second connecting portions 34b is used to prevent damage at the joint between the current collector (first current collector) 30 and the electrode assembly 10, and / or at the joint between the current collector (first current collector) 30 and the battery casing 20, during the sizing process. The sizing process refers to a compression process in which the height occupied by the rolled edge portion 21 of the battery casing 20 is reduced to decrease the overall height of the cylindrical battery 1 during manufacturing. By examining whether the bending portions B1 and B2 are formed and their different protruding directions, the degree of damage to the welded portion after the sizing process was confirmed through experiments. The results showed that almost no damage occurred in the cylindrical battery 1 with the structure where the bending portions B1 and B2 protrude towards the center of the cylindrical battery 1.

[0266] Reference Figures 17 to 20 This illustrates a portion of the manufacturing process of the cylindrical battery 1 of the present invention. First, referring to... Figure 17 A current collector 30 is placed on the electrode assembly 10 housed inside the battery casing 20, and then the first uncoated portion 11 protruding upwards from the electrode assembly 10 and the current collector 30 are welded together. In this case, the tab joint 32 of the current collector 30 is welded to a plurality of segmented pieces 11a provided on the first uncoated portion 11 (see reference). Figure 20 The bent surface 102 (refer to) Figure 15 In a modified example, the current collector 30 is pre-welded to the bent surface 102 before the electrode assembly 10 is housed inside the battery casing 20.

[0267] Next, refer to Figure 18 With the current collector 30 welded to the electrode assembly 10, the crimping cutter advances toward the interior of the battery casing 20. As a result, a crimped portion 21 is formed on the side wall of the battery casing 20, pressed inward toward the interior of the battery casing 20. The crimped portion 21 is located below the contact portion 33a of the current collector 30. Therefore, the contact portion 33a and the crimped portion 21 are then positioned for welding.

[0268] Next, refer to Figure 18 and Figure 19A contact portion 33a of the current collector 30 is disposed on the upper surface of the rolled edge portion 21. The current collector 30 and the rolled edge portion 21 are then welded together with the current collector 30 placed on the upper surface of the rolled edge portion 21. A housing cover 40, with its end surrounded by a sealing gasket G1, is placed on the upper surface of the contact portion 33a. The battery housing 20 is then bent to secure the housing cover 40 and the current collector 30 by surrounding the outer edge of the housing cover 40. This bending of the upper portion of the rolled edge portion 21 of the battery housing 20 forms a crimping portion 22, and the contact portion 33a of the housing cover 40 and the current collector 30 is fixed to the rolled edge portion 21 by the extension and bending shape of the crimping portion 22. The housing joint portion 33 is crimped and fixed by the crimping portion 22.

[0269] On the other hand, in this invention, the extending direction of the welding pattern formed between the first uncoated portion 11 and the tab joint portion 32 and the extending direction of the welding pattern formed between the rolled edge portion 21 and the first contact portion 33a are substantially perpendicular to each other. For example, the extending direction of the welding pattern formed between the first uncoated portion 11 and the tab joint portion 32 is the radial direction of the electrode assembly 10, and the extending direction of the welding pattern formed between the rolled edge portion 21 and the first contact portion 33a is the circumferential direction of the electrode assembly 10 (or the battery casing 20). In this case, the tangent drawn at any point in the circumferential direction is perpendicular to the radial direction. According to this structure, the bonding force between the current collector 30 and the electrode assembly 10 and the bonding strength between the current collector 30 and the battery casing 20 are enhanced. That is, according to this structure, even if vibration and / or impact are applied to the cylindrical battery 1 in any direction, the current collector 30, the electrode assembly 10, and the battery casing 20 remain firmly fixed.

[0270] Next, refer to Figure 19 and Figure 20 This illustrates a cylindrical battery whose overall height has been adjusted through a sizing process. The sizing process refers to a compression process during the manufacturing of a cylindrical battery, where the height occupied by the rolled edge portion 21 of the battery casing 20 is reduced to decrease the overall height. According to the sizing process, the battery casing 20 is compressed along the height direction (parallel to the Z-axis), thus achieving a shape where the rolled edge portion 21 of the electrode assembly 10 is pressed and partially compressed. On the other hand, according to the sizing process, the battery casing 20 is compressed along its length direction (vertical direction), thus the current collector 30 is bent by vertical pressure. That is, by performing the sizing process, the tab joint 32 bends upwards, thus there is a possibility that the weld between the tab joint 32 and the first uncoated portion 11 may be damaged. Therefore, the current collector 30 needs to have a structure that prevents damage to the weld between the tab joint 32 and the first uncoated portion 11 even after the sizing process.

[0271] For example, such as Figure 22 As shown in the figure, when the connecting portion (first connecting portion) 33b has an upward protruding shape, such as Figure 20 As illustrated, the effect of suppressing the upward tilting of the relative tab junction 32 is maximized. That is, when... Figure 19 When the battery casing 20 is compressed in the upward and downward directions, the tab joint 32 of the present invention is subjected to upward stress as the connecting portion 33b bends. However, as with the current collector 30 of the present invention, when the connecting portion 33b has a generally upward convex shape, the stress applied to the tab joint 32 can be minimized. Therefore, the tab joint 32 does not bend upward, and the welded state of the welded portion with the first uncoated portion 11 is well maintained.

[0272] More specifically, refer to Figure 22 and Figure 23 The connecting portion 33b before the precision pressing process has the following structure: it protrudes upward based on an imaginary straight line connecting the connecting portion 33a and the connecting portion 33b, and the connecting portion 33b and the tab joint portion 32, that is, an imaginary straight line connecting the two ends of the connecting portion 33b in the length direction. For example, the connecting portion 33b has at least one bend B1 forming an obtuse angle. On the other hand, the bend B1 is positioned closer to the top than an imaginary plane that passes through approximately the center of the imaginary straight line connecting the two ends of the connecting portion 33b and is parallel to the bottom surface of the battery casing 20. Preferably, the length of the connecting portion 33b from the bend B1 to the tab joint portion 32 is longer than the length of the connecting portion 33b from the bend B1 to the contact portion 33a.

[0273] Based on this structure, during the precision pressing process subjected to vertical pressure, the contact portion 33a descends downwards as indicated by the arrow, while the connecting portion 33b bulges upwards as indicated by the arrow (refer to the dotted line). More specifically, the connecting portion 33b bulges upwards more than the rolled edge portion 21. That is, before and after the precision pressing process, the outline of the outer shell joint portion 33 is as follows... Figure 22 and Figure 23This is where the change occurs. The degree of bulging of the aforementioned connecting portion 33b varies depending on the height change of the battery casing 20 caused by the precision pressing process. On the other hand, unlike the illustrated case, the position of the bent portion B1 only bulges up to the height level of the contact portion 33a. Due to this upward bulging of the connecting portion 33b, most of the stress can be absorbed in the connecting portion 33b, thus the stress applied to the welding area of ​​the tab joint 32 and the first uncoated portion 11 is relatively smaller. Therefore, according to the present invention, the phenomenon of the tab joint 32 warping upward does not occur. In addition, according to the above structure, the length of the connecting portion 33b from the bent portion B1 to the tab joint 32 is longer than the length of the connecting portion 33b from the bent portion B1 to the contact portion 33a, thus it is easier to insert into the interior of the battery casing 20 of the current collector 30, and stress dispersion can be effectively formed.

[0274] On the other hand, such as Figure 22 As shown, the shape deformation achieved by the protrusion of the connecting portion 33b can be formed into a generally curved shape that bulges upwards, or it can be different, such as... Figure 23 As shown in the diagram, it is formed into a straight line shape with the curved part B1 as the reference. Figure 23 As shown in the figure, when the shape is formed as a straight line bend, the region from the bend portion B1 to the contact portion 33a and the region from the bend portion B1 to the tab joint portion 32 in the connecting portion 33b respectively have a straight line shape.

[0275] The inventors have conducted in-depth research on the structure of the current collector 30 to prevent twisting and / or bulging of the current collector 30. The results show that when the connecting part 33b has an upward protruding structure, the damage to the weld between the tab joint 32 and the first uncoated part 11 is significantly reduced by performing a precision pressing process.

[0276] Figure 21 This is a diagram comparing the differences in the degree of weld damage caused by the shape of the current collector 30 prior to the precision pressing process. (Refer to...) Figure 21Example 1 shows a straight-line shape for the connecting portion 33b before fine pressing; Example 2 shows a downward-protruding shape for the connecting portion 33b before fine pressing; and Example 3 shows an upward-protruding shape for the connecting portion 33b before fine pressing. A 1mm fine pressing process was performed compared to Examples 1 to 3. In Example 1, where the connecting portion 33b is straight, the weld area between the connecting portion 33b and the tab joint 32 warped by approximately 0.72mm. In Example 2, where the connecting portion 33b bulged downward, the weld area between the connecting portion 33b and the tab joint 32 warped by approximately 0.99mm. That is, the warping was more severe in the case of the downward-protruding connecting portion 33b compared to the straight-line shape. On the other hand, in Example 3, where the connecting portion 33b bulged upward, the weld area between the connecting portion 33b and the tab joint 32 warped by approximately 0.02mm. This indicates that the warping was significantly alleviated compared to Examples 1 and 2. In other words, in Experimental Example 3, where the connecting portion 33b protrudes upwards, damage to the welded area between the tab joint and the first uncoated portion is minimized. This is because the degree of warping of the current collector 30 varies depending on the stress applied by the current collector 30 to the electrode assembly 10. Specifically, in Experimental Example 1, where the connecting portion 33b is straight, and Experimental Example 2, where the connecting portion 33b protrudes downwards, the stresses applied by the current collector 30 and the electrode assembly 10 to the welded portion during the pressing process are approximately 4.5 MPa and 3.7 MPa, respectively, which are very high, thus the warping of the current collector 30 is more severe. Conversely, in Experimental Example 3, where the connecting portion 33b protrudes upwards, the stress applied by the current collector 30 and the electrode assembly 10 to the welded portion during the pressing process is approximately 2.0 MPa, which is relatively low compared to Experimental Examples 1 and 2, thus the warping of the current collector 30 is relatively less.

[0277] Therefore, the preferred option is, as follows: Figure 22 As shown, the inclination of the connecting portion 33b is not fixed. Based on a predetermined location (e.g., the curved portion B1), the inclination of the upper region is less than that of the lower region. The predetermined location is positioned closer to the top than the middle portion of the connecting portion 33b. As a countermeasure, the connecting portion 33b has an upwardly protruding shape based on an imaginary straight line connecting the tab joint 32 and the contact portion 33a. The protruding shape can be a straight line connecting straight lines, a curved shape, or a combination of both. For example, as... Figure 22 or Figure 23As shown, the connecting portion 33b has at least one curved portion B1 based on the aforementioned designated location. Preferably, when viewed along the longitudinal axis of the battery casing 20, the at least one curved portion B1 is bent at an obtuse angle so as not to overlap with each other. Furthermore, the boundary between the contact portion 33a and the connecting portion 33b is formed by bending at an obtuse angle. Thus, as the connecting portion 33b approaches the rolled edge portion 21, the inclination of the connecting portion 33b gradually or progressively decreases.

[0278] In yet another aspect of the invention, referring to Figure 20 The angle θ between the tab joint 32 and the connecting portion 33b is, for example, 0 to 90 degrees. For instance, during the precision pressing process, when the upper end of the electrode assembly 10 rises to the height corresponding to the rolled edge 21, the tab joint 32 and the contact portion 33a are at the same height. That is, in this case, it corresponds to an angle θ between the tab joint 32 and the connecting portion 33b being approximately 0 degrees. Even when performing the precision pressing process, the contact portion 33a is preferably not positioned further down than the tab joint 32. This is because in this case, the first uncoated portion 11 is excessively pressed by the rolled edge 21, leading to damage. Therefore, the angle θ between the tab joint 32 and the connecting portion 33b is preferably 0 degrees or more. Alternatively, the angle θ between the tab joint 32 and the connecting portion 33b may increase to 90 degrees depending on the shape of the connecting portion 33b, which varies gradually or progressively in terms of length, thickness, or inclination. However, to avoid contact with the outer casing 40, the aforementioned angle θ is preferably no more than 90 degrees.

[0279] In another aspect of the invention, the connecting portion 33b may also support the outer casing 40. For example, the connecting portion 33b may be twisted upwards by a precision pressing process. In this case, the upwardly twisted connecting portion 33b contacts the outer casing 40. The connecting portion 33b serves to support the outer casing 40 upwards. Therefore, the current collector 30 is reliably fixed in the vertical direction by the precision pressing process. Thus, during the use of the cylindrical battery 1, even if vibration and / or impact occur, unnecessary vertical movement of the electrode assembly 10 inside the battery casing 20 can be prevented.

[0280] In another aspect of the invention, the upper surface and lower surface of the rolled edge portion 21 are asymmetrical with reference to an imaginary reference plane that is parallel to the bottom surface of the battery casing and passes through the innermost portion of the rolled edge portion 21. For example, referring to... Figure 20When the battery casing 20 is compressed in the vertical direction through the precision pressing process, the rolled edge portion 21 is also compressed in the vertical direction. At this time, the upper surface and the lower surface of the rolled edge portion 21 form an asymmetrical shape based on an imaginary reference plane (refer to the dashed line) passing through the innermost part of the rolled edge portion 21.

[0281] In another aspect of the invention, the pressing depth of the aforementioned rolled edge 21 is defined as PD. For example, refer to... Figure 24 The vertical distance from the inner side of the battery casing 20 to the innermost part of the rolled edge 21 is defined as the indentation depth PD. On the other hand, the shortest distance from the end of the contact portion 33a to the position of the vertical line passing through the innermost part of the rolled edge 21 is defined as the overlap length OV. That is, referring to... Figure 24 The overlap length OV refers to the radial length of the area where the curved portion 21 overlaps with the current collector 30 when viewed from the top of the rolled edge portion 21 downwards. At this time, the cylindrical battery 1 of the present invention satisfies the following relationship.

[0282] (R1, min +W bead，min ) / PD max ≤OV / PD≤(PD max -R2, min ) / PD max

[0283] In order to place the contact portion 33a of the current collector 30 onto the rolled edge portion 21 in a manner that allows for welding, the ratio is preferably (R1, R2, R3). min +W bead，min ) / PD max above. Reference Figure 24 In order to place the contact portion 33a of the current collector 30 on the rolled edge portion 21 in a weldable manner, a region that overlaps further than the radius of curvature R1 of the rolled edge portion 21 is required. For example, when the contact portion 33a overlaps the radius of curvature R1 of the rolled edge portion 21, since there is no flat area, the contact portion 33a and the rolled edge portion 21 only connect at one point. That is, the contact portion 33a cannot be stably placed on the rolled edge portion 21. Therefore, the contact portion 33a needs to overlap an additional region based on the radius of curvature R1 of the rolled edge portion 21. In this case, it is preferable that the length of the additional overlapping region is at least the weld width W. bead That is, in the additionally overlapping area, the contact portion 33a substantially overlaps with the rolled edge portion 21, and welding is performed in this area. Therefore, the length of the additionally overlapping area is at least the weld bead width W. beadOnly in this way can stable welding be performed without leaving the overlapping area. That is, the minimum overlap length for placing the contact portion 33a on the rolled edge portion 21 in a weldable manner is R1. min +W bead，min .

[0284] On another side, in order to place the contact portion 33a of the current collector 30 on the rolled edge portion 21 in a manner that allows for soldering, the ratio is preferably (PD). max -R2, min ) / PD max The following is for reference. Figure 24 A radius of curvature R2 exists in the boundary region between the rolled edge 21 and the inner surface of the battery casing 20. Therefore, when the contact portion 33a of the current collector 30 enters the boundary region between the rolled edge 21 (with radius of curvature R2) and the inner surface of the battery casing 20, the contact portion 33a cannot adhere tightly to the rolled edge 21 due to the radius of curvature R2 and instead lifts up. Therefore, the maximum overlap length for placing the contact portion 33a tightly on the rolled edge 21 is PD. max -R2, min .

[0285] As an example, the maximum value of the indentation depth PD of the rolled edge 21 is PD. max It is approximately 10mm, R1 ，min and R2, min The minimum values ​​are approximately 0.05 mm, W bead，min The overlap length OV is approximately 0.1 mm. At this point, the ratio of the overlap length OV to the indentation depth PD of the crimped portion 21 satisfies a range of approximately 1.5% to 99.5%. In order to place the contact portion 33a of the current collector 30 onto the crimped portion 21 in a manner suitable for soldering, this ratio is preferably approximately 1.5% or higher. The lower limit of the OV / PD ratio can be determined based on the maximum indentation depth PD of the crimped portion 21. max The minimum value of the radius of curvature R1, min and the minimum width W of the weld bead BD, which is the minimum width of the contact portion 33a that needs to contact the upper surface of the rolled edge portion 21 for welding the contact portion 33a. bead，min The length of the indentation is determined by the indentation depth. Specifically, as an example, the maximum value of the indentation depth PD is... max The minimum contact width W required for welding the contact portion 33a, i.e., the minimum width of the weld bead BD, is 10 mm. bead，min The length is 0.1 mm, and the minimum value of the radius of curvature R1 is... min The minimum overlap length OV is 0.15mm (=0.1mm+0.05mm), PDmax The depth is 10mm, therefore the lower limit of the OV / PD ratio is 1.5%. On the other hand, the portion of the contact portion 33a of the current collector 30 that contacts the flat portion of the upper surface of the rolled edge portion 21 at its maximum width is a portion separated from the inner side of the battery casing by a radius of curvature R2. Therefore, when the end of the contact portion 33a is located at this portion, the overlap length OV becomes maximum. The upper limit of the OV / PD ratio can be determined by the maximum value of the indentation depth and the minimum value of the radius of curvature R2. min The maximum indentation depth is 10 mm, and the minimum radius of curvature R2 is 0.05 mm. Under these conditions, the maximum overlap length OV is 9.95 mm (=10 mm - 0.05 mm), and PD... max The diameter is 10mm, therefore the upper limit of the OV / PD ratio is 99.5%.

[0286] In another aspect of the invention, the welding position for welding the rolled edge portion 21 and the contact portion 33a is defined as W. More specifically, the welding position W refers to the distance from the innermost part of the rolled edge portion 21 to the center of the weld bead BD located at the outermost contour in the radial direction. At this time, the welding position W and the indentation depth PD satisfy the following relationship.

[0287] (OV min -0.5*W bead，min ) / PD max ≤W / PD≤(OV max -0.5*W bead，min ) / PD max

[0288] The welding position W of the rolled edge portion 21 and the contact portion 33a is determined based on the overlap length of the contact portion 33a and the rolled edge portion 21 and the minimum width W of the weld bead BD. bead，min The welding position W is the central part of weld bead BD.

[0289] Reference Figure 24 The welding position where the contact portion 33a overlaps the rolled edge portion 21 with minimal overlap is defined as W1. The overlap length at this point is OV as described above. min On the other hand, in the overlapping area, weld bead BD needs to be formed for stable welding; therefore, the overlapping area must completely include weld bead BD. Thus, the welding position W1 should be from OV. min At least 0.5*W apart towards the inside of the rolled edge 21. bead，min The degree of location. Therefore, W1 satisfies the following relationship.

[0290] W1 = OV min -0.5*W bead，min

[0291] =R1, min +W bead，min -0.5*W bead，min

[0292] =R1, min +0.5*W bead，min

[0293] On the other hand, in order to minimize W1 / PD, the value of PD needs to be maximized. Therefore, the minimum value of W / PD is (OV). min -0.5*W bead，min ) / PD max .

[0294] From another perspective, refer to Figure 24 The welding position where the contact portion 33a enters the rolled edge portion 21 to the maximum extent is defined as W2. The overlap length at this time is OV as described above. max On the other hand, stable welding requires the weld bead BD to be formed within the overlapping area; therefore, the overlapping area must completely encompass the weld bead BD. Thus, the welding position W2 should be from OV... max At least 0.5*W apart towards the inside of the rolled edge 21. bead，min The degree of location. Therefore, W2 satisfies the following relationship.

[0295] W2 = OV max -0.5*W bead，min

[0296] =PD max -R2, min -0.5*W bead，min

[0297] On the other hand, in order to maximize the value of W2 / PD, make (PD) max -R2, min -0.5*W bead，min Divide by the value of PD, i.e., {1-(R2, min +0.5*W bead，min W2 / PD becomes the maximum. That is, when the value of PD is the maximum, the value of W2 / PD also becomes the maximum. Therefore, the maximum value of W / PD is (OV) / PD. min -0.5*W bead，min ) / PD max .

[0298] As an example, the minimum width required for welding the contact portion 33a to the rolled edge 21 is 0.1 mm. That is, the width of 0.1 mm corresponds to the minimum width of the weld bead BD formed by laser welding. Therefore, the welding position W1 when the contact portion 33a contacts the upper surface of the rolled edge 21 with the minimum width corresponds to a distance (R1, ...) from the innermost part of the rolled edge 21. min A region measuring approximately +0.5*0.1mm. Here, R1, min The minimum value of the radius of curvature R1 is, for example, 0.05 mm. When laser light is irradiated onto this area, a weld bead BD with a width of 0.1 mm is formed on the contact surface between the contact portion 33a and the rolled edge portion 21. The width of the weld bead BD also corresponds to the minimum contact width of the contact portion 33a. Based on the indentation depth PD of the rolled edge portion 21, the welding position W1 is a position separated by 0.1 mm from the innermost part of the rolled edge portion 21.

[0299] On the other hand, when the contact portion 33a contacts the upper surface of the rolled edge portion 21 at its maximum width, the end of the contact portion 33a is located at a curvature radius R2 separated from the inner side of the battery casing. min The position of degree. Here, R2, min The minimum value of the radius of curvature R2 is, for example, 0.05 mm. In this case, the welding position W2 closest to the end of the contact portion 33a is a portion spaced 0.05 mm from the end of the contact portion 33a. When laser is irradiated onto this portion, a weld bead with a minimum width of 0.1 mm is formed in a manner that connects to the end of the contact portion 33a. The welding position W2 when the contact portion 33a contacts the upper surface of the rolled edge portion 21 at its maximum width is spaced (PD-R2) based on the innermost portion of the rolled edge portion 21. min Areas with a thickness of -0.05mm. As an example, R2, min When the value is 0.05mm, the maximum value of the welding position W2 is the position separated by PD-0.1mm from the innermost part of the rolled edge 21.

[0300] Based on the above, R1, min and R2, minWhen the depth of penetration is 0.05 mm, the welding position W of the contact portion 33a, based on the penetration depth PD, is set within the range of (0.1 mm) to (PD - 0.1 mm) with the innermost part of the rolled edge portion 21 as the reference. The ratio of welding position W1 based on the penetration depth PD is the case where the penetration depth PD reaches its maximum value; therefore, the minimum value (%) of W1 / PD is 1% (=100*0.1 mm / 10 mm). Furthermore, the maximum value of the ratio W1 / PD of welding position W2 based on the penetration depth PD is the case where PD reaches its maximum value; therefore, the maximum value (%) of W2 / PD is 99% (=100*(10 mm - 0.1 mm) / 10 mm). In summary, the welding position area based on the penetration depth PD is the area ranging from 1% to 99% based on the penetration depth PD.

[0301] On the other hand, refer to Figure 24 W is defined as the distance from the innermost part of the rolled edge 21 when the overlap length is OV to the center of the weld bead BD located at the outermost contour in the radial direction. At this time, the cylindrical battery 1 of the present invention satisfies the following relationship.

[0302] W = OV - 0.5 * W bead，min

[0303] On another side, the aforementioned rolled edge 21 has a flat section F parallel to the lower surface of the battery casing 20 in at least a portion of its area, and the length of the flat section F of the rolled edge 21 that contacts the current collector 30 is 0V-R1. That is, referring to... Figure 23 The flat interval F corresponds to the length of the overlap length OV minus the curvature radius R1 of the rolled edge 21.

[0304] In another aspect of the invention, when the overlap length is OV, the width and length of the weld bead BD formed between the rolled edge portion 21 and the contact portion 33a, i.e., the weld pattern, in the radial direction is W. bead，min Above OV–R1 and below.

[0305] Reference Figure 24 The minimum width of weld bead BD is W bead，min Therefore, the minimum radial width of the weld pattern formed between the rolled edge 21 and the aforementioned contact portion 33a should be at least W. bead，min On the other hand, multiple weld beads BD can also be formed throughout the flat area F of the rolled edge portion 21. In this case, the multiple weld beads BD form a certain welding pattern. (Refer to...) Figure 23 The maximum value of the width and length in the radial direction of the welding pattern formed between the rolled edge portion 21 and the aforementioned contact portion 33a satisfies the following relationship.

[0306] The maximum value of the width and length in the radial direction of the weld pattern formed between the rolled edge portion 21 and the contact portion 33a

[0307] =W - W1 + minimum width of weld bead BD

[0308] =[(OV-0.5*W bead，min )-(R1+0.5*W bead，min )]+W bead，min

[0309] =OV-R1

[0310] In another aspect of the invention, the ratio of the radial width of the welded pattern to the length of the flat section F is approximately in the range of 10% to 40%. Preferably, the ratio is approximately in the range of 20% to 30%. When the ratio meets the above range, the weld strength increases with the increase of the welded area. Thus, the cylindrical battery 1 of the present invention can ensure high impact resistance.

[0311] In another aspect of the invention, the ratio of the area of ​​the current collector 30 that does not contact the upper surface of the electrode assembly 10 to the area of ​​a circle with the outer diameter of the electrode assembly 10 is defined as the aperture ratio of the current collector 30. The aperture ratio is calculated using the following mathematical formula.

[0312] Opening ratio (%)

[0313] = 1 - (area of ​​contact between the current collector and the upper surface of the electrode assembly) / (area of ​​a circle with the outer diameter of the electrode assembly as its diameter)

[0314] = (Area of ​​the current collector that does not contact the upper surface of the electrode assembly) / (Area of ​​a circle with the outer diameter of the electrode assembly as its diameter)

[0315] The aperture ratio of the aforementioned current collector 30 is, for example, approximately 30% or more and less than 100%, preferably approximately 60% or more and less than 100%. Figure 8Taking the case where the current collector 30 is placed on the electrode assembly 10 as an example, the areas where the current collector 30 contacts the electrode assembly 10 are the support portion 31 and the tab connection portion 32. In other words, the ratio of the area of ​​the current collector 30 in contact with the electrode assembly 10 to the area of ​​a circle with the outer diameter of the electrode assembly 10 is approximately 70% or less, preferably approximately 40% or less. When the opening ratio of the current collector 30 is within the above range, when electrolyte is injected, the electrolyte smoothly penetrates into the interior of the electrode assembly 10 through the opening area of ​​the current collector 30, represented by the current collector hole H2. That is, when the opening 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 opening area of ​​the current collector 30. In particular, there are tiny gaps between the overlapping surfaces of the segmented pieces 11a and between adjacent segmented pieces 11a. Therefore, the electrolyte permeates smoothly into the electrode assembly 10 through the capillary phenomenon caused by these gaps.

[0316] Reference Figure 13 and Figure 14 The distance A from the center of the current collector 30 to the end of the tab joint 32 is substantially the same as or shorter than the distance B from the center of the winding hole H1 of the electrode assembly 10 to the innermost part of the rolled edge 21 formed on the battery casing 20. In this case, interference between the rolled edge 21 and the current collector 30 can be prevented during the fine pressing process described above, thereby preventing damage to the current collector and / or the electrode assembly 10 caused by the rolled edge 21 pressing against the current collector 30.

[0317] Each tab joint 32 has at least one of the aforementioned weld beads W. The aforementioned weld beads W are formed not only in the tab joint 32, but may also be formed in the support portion 31 of the current collector 30.

[0318] The rolled edge portion 21 has a flat portion as described above. At least one weld bead W is formed between the rolled edge portion 21 and the first contact portion 33a. At least one weld bead W is formed as a straight-line welding pattern extending in a generally circumferential direction on the rolled edge portion 21. In contrast, at least one weld bead W formed between the rolled edge portion 21 and the first contact portion 33a is formed as an arc-shaped welding pattern extending in a generally circumferential direction on the rolled edge portion 21. The weld bead W formed on the first contact portion 33a has a shape extending in a circumferential direction. On another side, the welding pattern has a line shape formed by spot welding. On yet another side, multiple weld beads formed between the rolled edge portion 21 and the first contact portion 33a are formed within the same contact portion 33a.

[0319] On the other hand, when multiple first housing joint portions 33 are provided, although not shown, the first contact portions 33a respectively provided on the multiple first housing joint portions 33 are connected to each other to form a whole.

[0320] Reference Figure 1 The aforementioned outer cover 40 covers the opening formed on one side of the battery casing 20. The outer cover 40 is secured by a crimping portion 22 formed at the upper end of the battery casing 20. In this case, to improve the securing force and the sealing of the battery casing 20, a sealing gasket G1 is positioned between the battery casing 20 and the outer cover 40, and between the current collector 30 and the outer cover 40. In this case, the first contact portion 33a and / or the second contact portion 34a are positioned between the rolled edge portion 21 of the battery casing 20 and the sealing gasket G1. Thus, the first contact portion 33a and / or the second contact portion 34a positioned between the rolled edge portion 21 and the sealing gasket G1 are secured by bending the crimping portion 22 extending upward from the rolled edge portion 21.

[0321] On the other hand, in this invention, the outer casing 40 is not a component used as a channel for current. Therefore, the battery casing 20 and the outer casing 40 are firmly fixed by welding or by applying other components, and the application of such a sealing gasket G1 is not necessary as long as the sealing of the opening of the battery casing 20 can be ensured.

[0322] When the sealing gasket G1 is applied, the extension length of the portion of the sealing gasket G1 between the current collector 30 and the outer casing 40 is shorter than the extension length of the portion between the battery casing 20 and the outer casing 40. That is, the portion of the sealing gasket G1 surrounding the outer casing 40 and covering its lower surface has a shorter radial length than the portion covering its upper surface. If the sealing gasket G1 extends excessively towards the center of the cylindrical battery 1 inside the battery casing 20, interference between the sealing gasket G1 and the current collector 30 causes deformation of the current collector 30. This exerts force on the welded joint between the current collector 30 and the battery casing 20 and / or the welded joint between the current collector 30 and the first uncoated portion 11, leading to structural defects such as cracks. Therefore, by controlling the extension length of the sealing gasket G1 as described above, such defects can be prevented.

[0323] Reference Figure 1 and Figure 14The thickness of the sealing gasket G1 in the area contacting the first contact portion 33a is greater than its thickness in the area not in contact with the first contact portion 33a. The compression ratio of the sealing gasket G1 in the area contacting the first contact portion 33a is greater than that in the area not in contact with the first contact portion 33a. Since the area containing the first contact portion 33a and the area not containing the first contact portion 33a coexist, the thickness of the sealing gasket G1 changes alternately and repeatedly along the circumferential direction on the crimped edge portion 21. Because the area containing the first contact portion 33a and the area not containing the first contact portion 33a coexist, the thickness of the sealing gasket G1 alternately increases and decreases along the circumferential direction on the crimped edge portion 21. Because the area containing the first contact portion 33a and the area not containing the first contact portion 33a coexist, the compression ratio of the sealing gasket G1 changes along the circumferential direction on the crimped edge portion 21 in each area. This is because the degree of compression of the sealing gasket G1 differs between the region containing the first contact portion 33a and the region not containing the first contact portion 33a, resulting in a difference in its thickness. On the other hand, unlike this, by changing the thickness of the sealing gasket G1 at various locations, the compression rate of the sealing gasket G1 in the region contacting the first contact portion 33a and the region not contacting the first contact portion 33a can be made substantially the same. For example, the thickness of the sealing gasket G1 in the region not contacting the first contact portion 33a can be increased. In this case, it is possible to prevent the compression rate of the sealing gasket G1 in the region not containing the first contact portion 33a from being relatively lower than that in the surrounding region, thereby preventing a decrease in sealing performance in that region.

[0324] On the other hand, the aforementioned housing cover 40 includes a vent 41, which is used to prevent an increase in internal pressure caused by gas generated inside the battery housing 20. The vent 41 is formed in a portion of the housing cover 40, corresponding to a structurally weaker area than the surrounding region, so that it can easily break under internal pressure. The vent 41 is, for example, a region with a thickness thinner than the surrounding region.

[0325] The aforementioned terminal 50 penetrates the battery casing 20 on the opposite side of the open portion of the battery casing 20 and is electrically connected to the second uncoated portion 12 of the electrode assembly 10. The terminal 50 penetrates approximately to the center of the lower surface of the battery casing 20. The terminal 50 is electrically connected to the electrode assembly 10, for example, by connecting to a current collector (second current collector) 60 attached to the second uncoated portion 12 or by connecting to a lead connector (not shown) attached to the second uncoated portion 12. Therefore, the terminal 50 has the same polarity as the second electrode of the electrode assembly 10 and serves as the second electrode terminal T2. In the case where the second uncoated portion 12 is an anode tab, the terminal 50 is used as the anode terminal.

[0326] When considering the polarity and function of such a terminal 50, the terminal 50 needs to be insulated from the battery casing 20, which has the opposite polarity. For this purpose, an insulating pad G2 is applied between the terminal 50 and the battery casing 20. Alternatively, insulation can be achieved by coating a portion of the surface of the terminal 50 with an insulating material.

[0327] Similarly, the second uncoated portion 12 and / or the current collector (second current collector) 60 remain insulated from the battery casing 20. For this purpose, an insulator 70 is positioned between the second uncoated portion 12 and the battery casing 20, and / or between the current collector (second current collector) 60 and the battery casing 20. When the insulator 70 is used, the terminal 50 passes through the insulator 70 to achieve an electrical connection with the second uncoated portion 12.

[0328] On the other hand, in this invention, the outer surface 20a of the closed portion located on the opposite side of the open portion at the upper end of the battery casing 20 is used as the first electrode terminal T1. In the case where the first uncoated portion 11 is a cathode tab, the first electrode terminal T1 is the cathode terminal. The cylindrical battery 1 of this invention uses a terminal 50 exposed on the lower surface opposite to the open portion of the battery casing 20 as the second electrode terminal T2, and uses the remaining area in the lower surface of the battery casing 20 after removing the area occupied by the terminal 50 (including the area where the insulating pad G2 is exposed on the outer surface 20a of the closed portion to the outside of the terminal 50) as the first electrode terminal T1. Therefore, when multiple cylindrical batteries 1 are electrically connected, the anode and cathode are connected in one direction, simplifying the electrical connection structure. Furthermore, the cylindrical battery 1 of this invention has a structure in which a large portion of the lower surface opposite to the open portion of the battery casing 20 is used as the electrode terminal, thus ensuring sufficient area for welding components for electrical connection.

[0329] Reference Figure 1 and Figure 14 In the cylindrical battery 1 of the present invention, the current collector (first current collector) 30 is bonded to the inner surface of the first uncoated portion 11 and the battery casing 20. The current collector 30 includes a first portion that contacts the inner surface of the battery casing 20 and a second portion that is bonded to the first uncoated portion 11. In this case, when the central region of the first portion (approximately the center of the first portion along the circumferential direction of the electrode assembly 10) is projected onto the plane containing the second portion, the central region of the first portion and the second portion are arranged separately along the circumferential direction of the electrode assembly 10.

[0330] The sealing gasket G1 is located between the open portion of the battery casing 20 and the current collector 30. In this case, the first portion is located between the inner surface of the battery casing 20 and the sealing gasket G1. Preferably, the first portion is located between the rolled edge portion 21 of the battery casing 20 and the sealing gasket G1.

[0331] On the other hand, the first part and the second part are located on different planes in the winding axis direction of the electrode assembly 10. That is, the first part and the second part are arranged apart from each other along the height direction of the cylindrical battery 1 (the direction parallel to the Z-axis).

[0332] Reference Figure 1 and Figure 25 The aforementioned current collector (second current collector) 60 is bonded to the lower part of the electrode assembly 10. The current collector 60 is made of a conductive metallic material and is electrically bonded to the second uncoated portion 12. The bonding surface (bent surface) 102 formed by bending the end of the current collector 60 to the second uncoated portion 12 in a direction parallel to the current collector 60 (see reference) Figure 15 The bending direction of the second uncoated portion 12 is radial, for example, towards the core of the electrode assembly 10. With this bending shape, the space occupied by the second uncoated portion 12 in the vertical direction is reduced, thereby increasing energy density. Furthermore, when the current collector 60 is bonded to the bonding surface 102 formed by bending the second uncoated portion 12, the increased bonding area improves bonding strength and reduces contact resistance. The same applies to the first uncoated portion 11 described above.

[0333] The aforementioned current collector (second current collector) 60 includes a tab connection portion (second tab connection portion) 62 and a terminal connection portion 63. The current collector 60 also includes an edge portion 61. The edge portion 61 is disposed at the lower part of the electrode assembly 10 and has a generally rim shape with an empty space S formed therein. The accompanying drawings only illustrate the edge portion 61 as having a generally circular rim shape, but the invention is not limited thereto. The edge portion 61 may differ from the illustrated case, having a generally quadrilateral rim shape, a hexagonal rim shape, an octagonal rim shape, or other rim shapes.

[0334] The aforementioned tab-connecting portion 62 extends inward from the edge portion 61 and connects with the second uncoated portion 12. As described above, the connection between the current collector 60 and the second uncoated portion 12 is preferably configured such that it overlaps with the segmented sheet by at least approximately 50% within a relatively constant range of overlapping layers, where the number of overlapping layers is approximately at its maximum value. That is, the tab-connecting portion 62 of the current collector 60 connects with the second uncoated portion 12 in such a manner that it overlaps with the relatively constant range of overlapping layers by at least approximately 50%.

[0335] The terminal connection portion 63 is disposed separately from the tab connection portion 62. The terminal connection portion 63 is located inside the edge portion 61. The terminal connection portion 63 is joined to the terminal 50 (described later) by welding. To ensure the welding area for joining with the flat portion formed on the bottom surface of the terminal 50, the diameter of the terminal connection portion 63 is substantially the same as or larger than the diameter of the flat portion formed on the bottom surface of the terminal 50. The terminal connection portion 63 is, for example, located approximately at the center of the inner space surrounded by the edge portion 61.

[0336] The terminal connection portion 63 is positioned corresponding to the winding hole H1 formed in the core portion of the electrode assembly 10. The terminal connection portion 63 is configured to cover the winding hole H1 of the electrode assembly 10, preventing the winding hole H1 from being exposed to the outside. This prevents damage to the separation membrane located inside the hole due to the flow rate of the electrolyte passing through the hole, thus preventing the electrode from being exposed. Therefore, as described above, the terminal connection portion 63 has a larger diameter or width than the winding hole H1. However, the present invention does not preclude the possibility that the diameter of the terminal connection portion 63 is smaller than the diameter of the flat portion formed on the bottom surface of the terminal 50.

[0337] The aforementioned tab joint 62 and terminal joint 63 are not directly connected, but are arranged separately from each other and electrically connected through the edge portion 61. Thus, the current collector 60 of the present invention has a structure in which the tab joint 62 and terminal joint 63 are not directly connected but indirectly connected through the edge portion 61. Therefore, when the cylindrical battery 1 is subjected to impact and / or vibration, the impact applied to the joint between the tab joint 62 and the second uncoated portion 12 and the joint between the terminal joint 63 and the terminal 50 can be dispersed. Therefore, the current collector 60 of the present invention can minimize or prevent damage to the welded joint caused by external impact. More specifically, the current collector 60 of the present invention has a structure in which, when an external impact is transmitted to the inside of the battery 1 through the terminal 50, stress concentrates at the connection between the edge portion 61 and the terminal joint 63. However, such a connection is not a welded joint for joining components. Therefore, in the present invention, it is possible to effectively prevent product defects caused by damage to the welded joint due to external impact.

[0338] The outer diameter of the aforementioned current collector (second current collector) 60 is longer than the outer diameter of the current collector (first current collector) 30. The outer diameter of the second current collector 60 is twice the distance from its center to the end of the second tab connection 62 (or, if the second current collector 60 has an edge 61, the distance to the edge 61). The outer diameter of the first current collector 30 is twice the distance from its center to the outermost part of the first tab connection 32. In the case of the second current collector 60, it may have an outer diameter close to the inner diameter of the battery casing 20. The outer diameter of the second current collector 60 is approximately 33% to 98.5% of the inner diameter of the battery casing 20. The minimum value of the outer diameter of the second current collector 60 is a value used to prevent excessive increase in resistance. The maximum value of the outer diameter of the second current collector 60 is determined by considering tolerances such as those occurring during the manufacture of the current collector 60, assembly tolerances occurring when the electrode assembly 10 and the second current collector 60 are joined, tolerances occurring during the manufacture of the battery casing 20, and positional tolerances occurring when the combined electrode assembly 10 and the second current collector 60 are inserted into the battery casing 20. In this invention, when an insulator 70 is used, and the insulator 70 has a structure covering the upper end of the outer peripheral surface of the electrode assembly 10, the space for inserting the insulator 70 must also be considered. Therefore, the ratio of the outer diameter of the second current collector 60 to the inner diameter of the battery casing 20 is less than the aforementioned maximum value. Regarding the outer diameter of the second current collector 60, its size is limited to a level slightly smaller than the inner diameter of the battery casing 20, taking into account such tolerances. In the case of the first current collector 30, its diameter can be further limited to avoid interference during the sizing process. Thus, in order to avoid interference, the outer diameter of the first current collector 30 is approximately the same as or shorter than the inner diameter of the region where the rolled edge portion 21 of the battery casing 20 is formed.

[0339] On the other hand, when the outer diameter of the first current collector 30 and / or the second current collector 60 is set to T, the outer diameter of the electrode assembly 10 is set to JR, and the height of the segmented piece of the first uncoated portion 11 and / or the outermost segmented piece of the second uncoated portion 12 is set to F, the following relationship is satisfied. Here, the outer diameter of the first current collector 30 refers to twice the distance from the center of the first current collector 30 to the end of the first tab connection portion 32, and the outer diameter of the second current collector 60 refers to twice the distance from the center of the second current collector 60 to the end of the second tab connection portion 62 (or the outermost part of the edge portion 61).

[0340] JR–2*F≤T <JR

[0341] Preferably, the outer diameter T of the first current collector 30 and / or the second current collector 60 is greater than or equal to the length obtained by subtracting the height F of the outermost segment of the first uncoated portion 11 and / or the second uncoated portion 12 from the outer diameter JR of the electrode assembly 10. When this relationship is satisfied, the first tab joint 32 and / or the second tab joint 62 covers the end of the outermost segment 11a. That is, the first current collector 30 and / or the second current collector 60 has an outer diameter that covers the end of the segment bent in the last turn of the first electrode winding. In this case, welding can be performed while all the segment 11a forming the bent surface 102 with the first tab joint 32 and / or the second tab joint 62 (or edge portion 61) are uniformly pressed by the current collector 30, and the tight stacking state of the segment 11a can be well maintained after welding. A tight stacking state means, as... Figure 8 As illustrated, there are virtually no gaps between the segmented pieces. This tight stacking helps reduce the resistance of the cylindrical battery 1 to a level suitable for fast charging (e.g., below 4mΩ).

[0342] In another aspect, the outer diameter T of the first current collector 30 and / or the second current collector 60 is smaller than the outer diameter JR of the electrode assembly 10. If the outer diameter T of the first current collector 30 and / or the second current collector 60 is larger than the outer diameter JR of the electrode assembly 10, the dead space inside the battery casing 20 increases, adversely affecting the energy density of the cylindrical battery 1. Therefore, the outer diameter T of the first current collector 30 and / or the second current collector 60 is preferably smaller than the outer diameter JR of the electrode assembly 10.

[0343] On the other hand, the length L2 of the weld portion connecting the second tab joint 62 of the second current collector 60 to the second uncoated portion 12, extending along the radial direction of the electrode assembly 10, is longer than the length L1 of the weld portion connecting the first tab joint 32 of the first current collector 30 to the first uncoated portion 11, extending along the radial direction of the electrode assembly 10. For example, if the second current collector 60 is an aluminum anode current collector and the first current collector 30 is a copper cathode current collector, if the length L2 is longer than the length L1, the weld portion area of ​​the anode current collector, which has relatively lower conductivity, will be increased, thereby achieving a balance in the current flow in the anode and cathode current collectors. Here, the extension length of the weld portion connecting the current collectors 30, 60 and the uncoated portions 11, 12 refers to the extension length of the weld bead formed by welding.

[0344] Taking the core of the electrode assembly 10 as a reference, the distance to the starting point of the weld joint where the first tab joint 32 of the first current collector 30 and the first uncoated portion 11 are joined is substantially the same as the distance to the starting point of the weld joint where the second tab joint 62 of the second current collector 60 and the second uncoated portion 12 are joined. Here, "substantially the same" means that the two distances are identical or, for example, have a deviation of approximately 5% or less.

[0345] The current collector 60 further includes a bridging portion 64 extending inward from the edge portion 61 and connecting to the terminal connection portion 63. The bridging portion 64 has a tapered portion 64a whose width continuously and / or progressively narrows from the inner side of the edge portion 61 along the direction toward the terminal connection portion 63. The tapered portion 64a has a shape in which its width continuously and / or progressively widens from the connection point between the terminal connection portion 63 and the edge portion 61 along the direction toward the edge portion 61. With the tapered portion 64a, the rigidity of the components at the connection point between the bridging portion 64 and the edge portion 61 can be improved. With the tapered portion 64a, during the manufacturing process of the cylindrical battery 1, for example, by a transfer device and / or an operator holding the tapered portion 64a, the current collector 60 and / or the assembly of the current collector 60 and the electrode assembly 10 can be easily and safely transferred. That is, when the tapered portion 64a is provided, by holding the tab joint portion 62 or the terminal joint portion 63, which are welded to other components, product defects can be prevented.

[0346] The aforementioned tab connection portion 42 and / or bridging portion 44 are formed in multiple quantities. The number of the aforementioned tab connection portion 42 and / or bridging portion 44 is determined by taking into account the required resistance level in the cylindrical battery 1, the required aperture ratio in the current collector 60, etc.

[0347] Reference Figure 1 and Figure 26The aforementioned bridging portion 64 includes a current-cutting portion N for locally reducing the cross-sectional area of ​​the bridging portion 64. The reduction in the cross-sectional area of ​​the bridging portion 64 in the region formed by the current-cutting portion N is achieved, for example, by partially reducing the width and / or thickness. With the current-cutting portion N, the resistance in the region formed by the current-cutting portion N increases, thereby enabling rapid current interruption by breaking the current in the current-cutting portion N when an overcurrent occurs. Multiple current-cutting portions N are formed along the length direction of the bridging portion 64. When multiple bridging portions 64 are provided, the current-cutting portion is provided in at least one of the multiple bridging portions 64. In the figures of this invention, only the case where the current-cutting portion N has a recessed shape is illustrated, but the invention is not limited to this; for example, it may also be formed in a groove shape and / or a through-hole shape. On the other hand, although not shown, a strip in the shape of surrounding the bridging portion 64 can be applied to the region where the current-cutting portion N is formed. When the above-mentioned strip is used, it is possible to prevent foreign matter such as molten metal generated when the current cut-off section N breaks from splashing onto other components and causing short circuits. In addition, the heat generated by the current cut-off section N is not transferred to the outside, so the current cut-off section N may break more quickly.

[0348] On the other hand, to prevent foreign matter generated during breakage from entering the interior of the electrode assembly 10, the aforementioned current-cutting portion N is preferably located in a region corresponding to the uniform stacking range of the second uncoated portion 12. This is because, in this region, the overlapping layer number of the segmented pieces of the second uncoated portion 12 remains at its maximum, thereby the overlapping segmented pieces are used as a mask. The aforementioned current-cutting portion N is formed, for example, at a location approximately 40% to 90% of the radius of the electrode assembly 10 along the radial direction from the core of the electrode assembly 10. Preferably, the aforementioned current-cutting portion N is located approximately at the center between the core and the outermost edge of the electrode assembly 10.

[0349] Reference Figures 27 to 30 The structure of the electrode assembly 10 described above will be explained in more detail below. The following description uses the first electrode of the first electrode and the second electrode described above as examples, but the same structure of the first electrode is also applied to the second electrode.

[0350] Reference Figures 27 to 30 The first electrode 110 includes a sheet-shaped first electrode current collector 111 made of a conductive foil, a first active material layer 112 formed on at least one side of the first electrode current collector 111, and a first uncoated portion 11 formed at the long side end of the first electrode current collector 111 where no active material is coated.

[0351] Preferably, the first uncoated portion 11 includes a plurality of segmented pieces 11a that have undergone notching. The plurality of segmented pieces 11a form multiple groups, and the height (length in the Z direction) and / or width (length in the X direction) and / or spacing of the segmented pieces 11a belonging to each group are substantially the same. The number of segmented pieces 11a belonging to each group may be increased or decreased compared to the number shown in the figure. The segmented pieces 11a have a shape that combines at least one straight line and / or at least one curve into a geometric figure. Preferably, the segmented pieces 11a are trapezoidal, but can be deformed into quadrilaterals, parallelograms, semicircles, or semi-ellipses, etc.

[0352] Preferably, the height of the segmented piece 11a increases progressively from the core side toward the outer periphery along a direction parallel to the winding direction of the electrode assembly 10. Furthermore, the uncoated portion 11-1 on the core side adjacent to the core side of the electrode assembly 10 may not include the segmented piece 11a, and the height of the uncoated portion 11-1 on the core side is lower than that of other uncoated portions. Additionally, the uncoated portion 11-2 on the outer periphery side adjacent to the outer periphery side of the electrode assembly 10 does not include the segmented piece 11a, and the height of the uncoated portion 11-2 on the outer periphery side is lower than that of other uncoated portions.

[0353] Optionally, the first electrode 110 includes an insulating coating E covering the boundary between the active material layer 112 and the first uncoated portion 11. The insulating coating E comprises an insulating polymer resin and optionally includes an inorganic filler. The insulating coating E prevents the end of the active material layer 112 from contacting an active material layer of opposite polarity through the separation membrane and structurally supports the bending of the segmented sheet 11a. Therefore, when the first electrode 110 is wound to form the electrode assembly 10, at least a portion of the insulating coating E is preferably exposed to the outside from the separation membrane.

[0354] Reference Figure 27 and Figure 28 The aforementioned electrode assembly 10 is constructed by... Figure 2 The membrane is manufactured using the winding process described herein. For ease of explanation, the protruding structures of the uncoated portions 11 and 12 extending outward from the separation membrane are shown in detail, while the diagrams of the winding structures of the first electrode, the second electrode, and the separation membrane are omitted. The first uncoated portion 11, protruding upward, extends from the first electrode, and the second uncoated portion 12, protruding downward, extends from the second electrode.

[0355] A schematic illustration shows the pattern of varying heights of the uncoated portions 11 and 12. Specifically, the heights of the uncoated portions 11 and 12 vary irregularly depending on the position of the cut cross-section. For example, when the side portion of the trapezoidal segment 11a is cut, the height of the uncoated portion on the cross-section is lower than the height of the segment 11a. Therefore, the heights of the uncoated portions 11 and 12 illustrated in the cross-section of the electrode assembly 10 correspond to the average height of the uncoated portions included in each winding coil.

[0356] Reference Figures 27 to 30 The uncoated portions 11 and 12 are bent, for example, from the outer periphery to the core side along the radial direction of the electrode assembly 10. Figure 28 The locations where bending occurs in the uncoated portions 11 and 12 are indicated by dashed boxes. When the uncoated portions 11 and 12 are bent, adjacent segments in the radial direction overlap to form multiple layers, creating bending surfaces 102 on the upper and lower parts of the electrode assembly 10. At this time, the core-side uncoated portion ( Figure 27 Because of its low height, the segment 11a (11-1) is not bent. The height h of the segment 11a bent on the innermost side is approximately the same as or shorter than the length r of the winding area formed by the uncoated core portion 11-1 without segment structure and 10% of the winding hole diameter. Therefore, the hole formed in the core portion C of the electrode assembly 10 is not closed. The fact that the hole is not closed makes it easy to perform electrolyte injection in the electrolyte injection process, thus improving the electrolyte injection efficiency. In addition, the welding tool can be inserted through the hole to easily perform welding of the terminal 50 and the second current collector 60 (see reference). Figure 13 ).

[0357] On the other hand, refer to Figure 31 Multiple cylindrical batteries 1 are connected in series and parallel at the top of the cylindrical batteries 1 via a bus 150. The number of cylindrical batteries 1 increases or decreases depending on the capacity of the battery pack.

[0358] In each cylindrical battery 1, for example, terminal 50 is anode, and the outer surface 20a of the closing portion of battery casing 20 is cathode. Of course, the opposite is also possible. Both the terminal 50 of the aforementioned cylindrical battery 1 and the outer surface 20a of the closing portion located opposite the opening of battery casing 20 are arranged facing upwards (as opposed to...). Figure 1 The shape shown in the illustration is reversed, flipped upside down.

[0359] Preferably, the plurality of cylindrical batteries 1 are arranged in multiple columns and rows. Columns are in a vertical direction relative to the ground, and rows are in a horizontal direction relative to the ground. Furthermore, to maximize space efficiency, the cylindrical batteries 1 are arranged in a closest packing structure. The closest packing structure is formed when the centers of the exposed portions of the terminals 50 exposed to the outside of the battery casing 20 are connected to each other to form an equilateral triangle. Preferably, the bus 150 is arranged on the upper part of the plurality of cylindrical batteries 1, more preferably between adjacent columns. As a countermeasure, the bus 150 is arranged between adjacent rows.

[0360] Preferably, the bus 150 connects the batteries 1 arranged in the same column in parallel with each other, and connects the cylindrical batteries 1 arranged in two adjacent columns in series with each other.

[0361] Preferably, the bus 150 includes a main body 151, a plurality of first bus terminals 152 and a plurality of second bus terminals 153 for serial and parallel connections.

[0362] The main body 151 extends between the terminals 50 of adjacent cylindrical batteries 1, preferably between rows of cylindrical batteries 1. As a countermeasure, the main body 151 extends along the rows of cylindrical batteries 1, and is bent regularly in a zigzag shape.

[0363] Multiple first bus terminals 152 extend from one side of the main body 151 toward the terminals 50 of each cylindrical battery 1 and are electrically connected to the terminals 50. The electrical connection between the first bus terminals 152 and the terminals 50 is achieved by laser welding, ultrasonic welding, or the like. Furthermore, multiple second bus terminals 153 are electrically connected from the other side of the main body 151 to the outer surface 20a of each cylindrical battery 1. The electrical connection between the second bus terminals 153 and the outer surface 20a is achieved by laser welding, ultrasonic welding, or the like.

[0364] Preferably, the main body 151, the plurality of first bus terminals 152, and the plurality of second bus terminals 153 are constituted by a conductive metal plate. The metal plate is, for example, an aluminum plate or a copper plate, but the present invention is not limited thereto. In a variation, the main body 151, the plurality of first bus terminals 152, and the second bus terminals 153 can be manufactured into multiple block units and then joined together by welding or the like.

[0365] In the cylindrical battery 1 of the present invention, the anode terminal 50 and the outer surface 20a of the closing portion of the cathode battery casing 20 are located in the same direction, so the electrical connection of the cylindrical battery 1 can be easily realized by means of the bus 150.

[0366] In addition, the outer surface 20a of the terminal 50 of the cylindrical battery 1 and the closing portion of the battery casing 20 has a wide area, so the contact area of ​​the bus 150 can be sufficiently ensured, thereby sufficiently reducing the resistance of the battery pack including the cylindrical battery 1.

[0367] Preferably, the cylindrical battery is, for example, a cylindrical battery with a shape factor ratio (a value obtained by dividing the diameter of the cylindrical battery by its height, i.e., defined by the ratio of diameter Φ to height H) that is approximately greater than 0.4.

[0368] Here, shape factor refers to the values ​​representing the diameter and height of the cylindrical battery. An embodiment of the cylindrical battery of this invention includes, for example, a 46110 battery, a 4875 battery, a 48110 battery, a 4880 battery, and a 4680 battery. In the numerical values ​​representing the shape factor, the first two digits represent the diameter of the battery, and the next two digits represent the height of the battery.

[0369] One embodiment of the present invention is a cylindrical battery with a generally cylindrical shape, having a diameter of approximately 46 mm, a height of approximately 110 mm, and a shape factor ratio of approximately 0.418.

[0370] Another embodiment of the cylindrical battery is a generally cylindrical battery with a diameter of approximately 48 mm, a height of approximately 75 mm, and a shape factor ratio of approximately 0.640.

[0371] Another embodiment of the cylindrical battery is a generally cylindrical battery with a diameter of approximately 48 mm, a height of approximately 110 mm, and a shape factor ratio of approximately 0.436.

[0372] Another embodiment of the cylindrical battery is a generally cylindrical battery with a diameter of approximately 48 mm, a height of approximately 80 mm, and a shape factor ratio of approximately 0.600.

[0373] Another embodiment of the cylindrical battery is a generally cylindrical battery with a diameter of approximately 46 mm, a height of approximately 80 mm, and a shape factor ratio of approximately 0.575.

[0374] Previously, batteries with a shape factor ratio of approximately 0.4 or less were used. For example, 1865 and 2170 batteries were previously used. In the case of an 1865 battery, its diameter is approximately 18 mm and its height is approximately 65 mm, resulting in a shape factor ratio of approximately 0.277. In the case of a 2170 battery, its diameter is approximately 21 mm and its height is approximately 70 mm, resulting in a shape factor ratio of approximately 0.300.

[0375] Reference Figure 32 A battery pack 3 according to one embodiment of the present invention includes a battery assembly consisting of multiple cylindrical batteries 1 electrically connected as described above, and a packaging shell 2 for housing the battery assembly. In the figures of the present invention, for ease of illustration, components such as the bus for electrical connection, cooling unit, and power terminals are omitted. Regarding the electrical connection structure of the multiple batteries 1 used to manufacture the battery pack 3, in the above... Figure 31 An illustrative explanation is provided in the text.

[0376] Reference Figure 33 In one embodiment of the present invention, the vehicle 5 is, for example, an electric vehicle, a hybrid vehicle, or a plug-in hybrid vehicle, including a battery pack 3 according to one embodiment of the present invention. The vehicle 5 includes both four-wheeled and two-wheeled vehicles. The vehicle 5 operates by receiving power from the battery pack 3 according to one embodiment of the present invention.

[0377] According to the present invention, resistance can be significantly reduced when electrically connecting the electrode assembly and the battery casing. In another aspect, according to the present invention, the bonding strength at the joint between the current collector and the battery casing can be improved. In yet another aspect, according to the present invention, the energy density of the cylindrical battery can be increased. In yet another aspect, according to the present invention, the ease of the welding process for electrically connecting the battery casing and the current collector is improved during the manufacture of the cylindrical battery, thereby improving productivity. In yet another aspect, according to the present invention, the possibility of damage to the welded joints between the current collector and the electrode assembly and / or between the current collector and the battery casing can be significantly reduced even when vibration and impact are applied during battery use. Furthermore, according to the present invention, the ease of the welding process for electrically connecting the battery casing and the current collector is improved during the manufacture of the cylindrical battery, thereby improving productivity.

[0378] While the present invention has been described above with reference to specific embodiments and accompanying drawings, the present invention is not limited thereto. Within the technical concept of the present invention and the equivalent scope described below, those skilled in the art can make various modifications and variations.

Claims

1. A battery, characterized in that, It includes: An electrode assembly is an electrode assembly in which a first electrode, a second electrode and a separation membrane between them are wound around a winding shaft to define the core and the outer peripheral surface. The first electrode has a first uncoated portion at its long side end along the winding direction, which is not coated with an active material layer and is exposed to the outside of the separation membrane. At least a portion of the first uncoated portion itself is used as an electrode tab. The battery casing has an opening on one side, through which the electrode assembly is housed; A first current collector includes: a support portion disposed on the upper part of the electrode assembly; a first tab connection portion extending from the support portion and connected to the first uncoated portion; and a first housing connection portion extending from the support portion and electrically connected to the inner surface of the battery housing; and The outer casing seals the aforementioned open portion. The first electrode lug joint and the first outer shell joint are not directly connected, but are indirectly connected through the support portion. The battery casing includes a rolled edge portion formed at the end adjacent to the open portion and pressed inward. The aforementioned first outer shell joint includes: The first contact portion is attached to the rolled edge portion of the aforementioned battery casing; and The first connecting portion connects the aforementioned support portion and the aforementioned first contact portion, and The first contact portion is welded to the upper surface of the rolled edge portion.

2. The battery according to claim 1, characterized in that, The aforementioned first electrode joint has at least one injection hole.

3. The battery according to claim 1, characterized in that, The first connecting portion has a structure that protrudes upward based on an imaginary straight line connecting the two ends of the first connecting portion in the length direction.

4. The battery according to claim 1, characterized in that, The first connecting portion has a structure that protrudes upwards compared to the rolled edge portion.

5. The battery according to claim 1, characterized in that, The aforementioned rolled edge includes: The upper rolled edge, centered on the innermost part that is pressed inward, is located at the top; and The lower rolled edge is located below, centered on the innermost part that is pressed inward.

6. The battery according to claim 5, characterized in that, The aforementioned upper rolled edge portion and the aforementioned lower rolled edge portion are asymmetrical with reference to an imaginary reference plane that is parallel to the bottom surface of the aforementioned battery casing and passes through the innermost part of the aforementioned rolled edge portion.

7. The battery according to claim 5, characterized in that, At least one of the first electrode tabs of the first current collector is disposed closer to the lower side than the lower rolled edge portion.

8. The battery according to claim 5, characterized in that, At least one of the aforementioned upper rolled edge portion and the aforementioned lower rolled edge portion is inclined at a predetermined angle to the lower surface of the aforementioned battery casing.

9. The battery according to claim 8, characterized in that, The first contact portion is disposed on the inclined upper surface of the rolled edge portion.

10. The battery according to claim 5, characterized in that, At least one of the aforementioned upper rolled edge portion and the aforementioned lower rolled edge portion is parallel to the lower surface of the aforementioned battery casing in at least a portion of the region.

11. The battery according to claim 10, characterized in that, The first contact portion is disposed on the flat upper surface of the rolled edge portion.

12. The battery according to claim 5, characterized in that, The aforementioned first contact portion is welded to a flat area formed on the aforementioned upper rolled edge portion.

13. The battery according to claim 1, characterized in that, The first contact portion has an arc shape that extends in the circumferential direction along at least a portion of the rolled edge of the battery casing.

14. The battery according to claim 1, characterized in that, The first contact portion has an arc shape that extends in opposite directions along the circumferential direction from the intersection of the first connecting portion and the first contact portion on the rolled edge portion.

15. The battery according to claim 1, characterized in that, The pressing depth of the aforementioned rolled edge is set to PD. Let the minimum radius of curvature of the aforementioned rolled edge be R1. ，min , Set the minimum weld width to W. bead，min , The minimum radius of curvature in the boundary region between the aforementioned rolled edge and the inner surface of the battery casing is set as R2. ，min When the following equation is satisfied, PD≥R1 ，min +R2 ，min +W bead，min 。 16. The battery according to claim 1, characterized in that, The pressing depth of the above-mentioned rolled edge is 0.2~10mm.

17. The battery according to claim 1, characterized in that, The pressing depth of the aforementioned rolled edge is set to PD, and the maximum value of the aforementioned pressing depth is set to PD. max , The shortest distance from the end of the first contact portion to the vertical line passing through the innermost part of the rolled edge portion, i.e., the overlap length, is set as OV. Let the minimum radius of curvature of the aforementioned rolled edge be R1. ，min , Set the minimum weld width to W. bead，min , The minimum radius of curvature in the boundary region between the aforementioned rolled edge and the inner surface of the battery casing is set as R2. ，min When the following equation is satisfied, (R1 ，min +W bead，min ) / PD max ≤OV / PD≤(PD max -R2 ，min ) / PD max 。 18. The battery according to claim 1, characterized in that, The welding area between the first contact portion and the rolled edge portion is narrower than the flat upper surface of the rolled edge portion.

19. The battery according to claim 1, characterized in that, The pressing depth of the aforementioned rolled edge is set to PD, and the maximum value of the aforementioned pressing depth is set to PD. max , Let W be the distance from the innermost part of the rolled edge to the center of the weld bead located on the outermost contour in the radial direction. The shortest distance from the end of the first contact portion to the vertical line passing through the innermost part of the rolled edge portion, i.e., the overlap length, is set as OV, and the minimum value of OV is set as OV. min Set the maximum value of OV to OV. max , Set the minimum weld width to W. bead，min When the following equation is satisfied, (OV min -0.5 W bead，min ) / PD max ≤W / PD≤(OV max –0.5 W bead，min ) / PD max 。 20. The battery according to claim 19, characterized in that, Let W1 be the minimum distance from the innermost part of the rolled edge to the center of the weld bead located on the outermost contour in the radial direction. When the distance W is defined as the distance from the innermost part of the rolled edge when the overlap length is OV to the center of the weld bead located at the outermost contour in the radial direction, the following formula is satisfied: W1=R1+0.5 W bead，min W=OV-0.5 IN bead，min 。 21. The battery according to claim 19, characterized in that, The aforementioned rolled edge portion has a flat section in at least a portion of its area that is parallel to the lower surface of the aforementioned battery casing. With an overlap length of OV, When the radius of curvature of the rolled edge is R1, The length of the flat section of the rolled edge that contacts the first current collector is OV–R1.

22. The battery according to claim 21, characterized in that, The width and length of the welding pattern formed between the rolled edge and the first contact portion in the radial direction is W. bead，min Above and below OV–R1.

23. The battery according to claim 22, characterized in that, The ratio of the width and length of the above-mentioned welding pattern in the radial direction to the length of the above-mentioned flat interval satisfies the range of 10% to 40%.

24. The battery according to claim 1, characterized in that, The first connecting portion has at least one first curved portion, which changes its extension direction at least once.

25. The battery according to claim 24, characterized in that, The aforementioned first curved portion is positioned closer to the top than an imaginary plane that passes through the center of an imaginary straight line connecting one end of the aforementioned first contact portion and one end of the aforementioned first tab joint portion and is parallel to the bottom surface of the aforementioned battery casing.

26. The battery according to claim 24, characterized in that, The aforementioned first curved portion is bent at an obtuse angle so that it does not overlap with each other when viewed along the axis in the length direction of the aforementioned battery casing.

27. The battery according to claim 24, characterized in that, The boundary between the first contact portion and the first connecting portion is bent into an obtuse angle.

28. The battery according to claim 26, characterized in that, The first connecting portion has a shape in which its inclination gradually decreases as it approaches the rolled edge portion.

29. The battery according to claim 1, characterized in that, The angle between the first electrode lug joint and the first connecting part is between 0 and 90 degrees.

30. The battery according to claim 1, characterized in that, The first connecting portion supports the outer casing cover.

31. The battery according to claim 1, characterized in that, The aforementioned first electrode joint and the aforementioned first contact portion are located at substantially the same height.

32. The battery according to claim 1, characterized in that, The first contact portion has a flat surface that engages with the upper surface of the rolled edge portion facing the open portion.

33. The battery according to claim 1, characterized in that, The first current collector described above has a current collector hole formed at its center.

34. The battery according to claim 33, characterized in that, The aforementioned current collector hole is located at a position corresponding to the winding hole formed in the center of the aforementioned electrode assembly.

35. The battery according to claim 34, characterized in that, The diameter of the current collector hole is greater than or equal to the diameter of the winding hole provided in the core of the electrode assembly.

36. The battery according to claim 1, characterized in that, The first current collector also includes a second housing connection portion, which extends from the end of one of the plurality of first tab connections and is connected to the inner side of the battery housing.

37. The battery according to claim 36, characterized in that, The aforementioned second outer shell joint includes: The second contact portion is attached to the inner side of the aforementioned battery casing; and The second connecting portion connects the end of one of the plurality of first tab connecting portions to the second contact portion.

38. The battery according to claim 37, characterized in that, The second contact portion has a shape in which at least a portion extends along the inner circumferential surface of the battery casing.

39. The battery according to claim 37, characterized in that, The second connecting portion has at least one second bend, which changes its extension direction at least once.

40. The battery according to claim 1, characterized in that, The distance from the center of the first current collector to the end of the first tab joint is substantially the same as or shorter than the distance from the center of the winding hole of the electrode assembly to the innermost part of the rolled edge.

41. The battery according to claim 1, characterized in that, The upper surface of the aforementioned rolled edge portion has a flat portion.

42. The battery according to claim 12, characterized in that, The weld bead formed between the rolled edge portion and the first contact portion is at least one. At least one of the aforementioned weld beads forms a weld pattern in the shape of a straight line extending along the circumferential direction.

43. The battery according to claim 12, characterized in that, The weld bead formed between the rolled edge portion and the first contact portion is at least one. At least one of the aforementioned weld passes forms an arc-shaped weld pattern that extends along the circumferential direction.

44. The battery according to claim 12, characterized in that, The weld bead formed between the rolled edge and the first contact portion forms a weld pattern. The aforementioned welding pattern has a line shape formed by connecting spot welds.

45. The battery according to claim 1, characterized in that, Multiple weld beads are formed between the rolled edge portion and the first contact portion.

46. ​​The battery according to claim 1, characterized in that, The second electrode further includes a second uncoated portion at its long side end along the winding direction, which is not coated with an active material layer and is exposed to the outside of the separation membrane. At least a portion of the second uncoated portion itself serves as an electrode tab. The battery also includes a terminal that extends through the battery casing from the opposite side of the opening and is electrically connected to the second uncoated portion.

47. The battery according to claim 46, characterized in that, It also includes: The battery also includes a second current collector located between the electrode assembly and the terminals. The aforementioned second current collector includes: The second electrode tab is attached to the aforementioned second uncoated portion; and Terminal connection portion, which is connected to the aforementioned terminal.

48. The battery according to claim 47, characterized in that, The aforementioned terminal joint covers the winding hole of the aforementioned electrode assembly.

49. The battery according to claim 47, characterized in that, The outer diameter of the second collector is larger than the outer diameter of the first collector.

50. The battery according to claim 47, characterized in that, The aforementioned second electrode lug is joined to the joint surface formed by bending the aforementioned second uncoated portion.

51. The battery according to claim 1, characterized in that, The battery casing has a crimping portion formed on the upper part of the rolled edge portion and extends and bends in a manner that surrounds the outer edge of the casing cover.

52. The battery according to claim 51, characterized in that, The first outer shell joint is pressed and fixed by the pressing part.

53. The battery according to claim 51, characterized in that, The battery also includes a sealing gasket disposed within the crimping portion and between the battery casing and the casing cover.

54. The battery according to claim 53, characterized in that, The first contact portion is located between the rolled edge portion and the sealing gasket.

55. The battery according to claim 54, characterized in that, The first contact portion is fixed by bending the crimping portion.

56. The battery according to claim 53, characterized in that, The thickness of the sealing gasket in the area that contacts the first contact portion is greater than its thickness in the area that does not contact the first contact portion.

57. The battery according to claim 53, characterized in that, The compression ratio of the sealing gasket in the area that contacts the first contact portion is greater than that in the area that does not contact the first contact portion.

58. The battery according to claim 53, characterized in that, The compression ratio of the aforementioned sealing gasket in the area in contact with the aforementioned first contact portion is substantially the same as the compression ratio in the area not in contact with the aforementioned first contact portion.

59. The battery according to claim 53, characterized in that, The thickness of the sealing gasket changes in each region along the circumferential direction on the aforementioned rolled edge.

60. The battery according to claim 53, characterized in that, The thickness of the aforementioned sealing gasket alternately increases and decreases along the circumferential direction on the aforementioned rolled edge portion.

61. The battery according to claim 53, characterized in that, Along the circumferential direction on the aforementioned rolled edge, the compression ratio of the aforementioned gasket changes in each region.

62. The battery according to claim 1, characterized in that, The first outer shell joint is elastically biased on the rolled edge portion.

63. The battery according to claim 27, characterized in that, The connection portion of the first contact portion and the first connecting portion matches the inner surface of the rolled edge portion.

64. The battery according to claim 1, characterized in that, At least a portion of the first uncoated portion includes a plurality of segmented pieces divided along the winding direction of the electrode assembly. The aforementioned segmented pieces are bent along the radial direction of the aforementioned electrode assembly to form a bent surface.

65. The battery according to claim 64, characterized in that, The aforementioned multiple segmented pieces are overlapped in multiple layers to form a bent surface. The aforementioned bending surface includes a range where the number of overlapping layers increases from the outer periphery of the electrode assembly toward the core side until it reaches a maximum value, and a range where the number of overlapping layers is uniform from the radius where the number of overlapping layers reaches a maximum value to the radius where the innermost segment exists.

66. The battery according to claim 65, characterized in that, The first tab joint is joined to the bending surface in such a way that it overlaps with the uniform interval of the stacked layers.

67. The battery according to claim 66, characterized in that, The number of overlapping layers in the above-mentioned uniform layer number interval is 10 or more.

68. The battery according to claim 67, characterized in that, The first tab joint is welded to the bending surface, and the welding area of ​​the tab joint overlaps with the uniform stacking interval by at least 50% along the radial direction of the electrode assembly.

69. The battery according to claim 1, characterized in that, The first uncoated portion and the first tab joint portion are joined together by welding along the radial direction of the electrode assembly.

70. The battery according to claim 1, characterized in that, The first tab joint is welded to the first uncoated part in a manner parallel to the lower surface of the battery casing.

71. The battery according to claim 69, characterized in that, The weld bead formed between the first uncoated portion and the first tab joint portion forms a straight weld pattern that extends along the radial direction of the electrode assembly.

72. The battery according to claim 69, characterized in that, A weld pattern is formed in the weld bead between the first uncoated portion and the first electrode tab joint portion. The aforementioned welding pattern has a line shape formed by connecting spot welds.

73. The battery according to claim 69, characterized in that, The width of the weld bead formed between the first uncoated portion and the first tab joint portion is 0.1 mm or more.

74. The battery according to claim 1, characterized in that, The aforementioned first electrode tab joint and the aforementioned first outer shell joint are each formed in multiple portions. The aforementioned first electrode tab joints and first housing joints are arranged radially, cross-shaped, or combined with the center portion of the aforementioned first current collector.

75. The battery according to claim 74, characterized in that, Multiple of the aforementioned first outer shell joints are respectively disposed between adjacent first tab joints.

76. The battery according to claim 1, characterized in that, The aforementioned first outer shell joint is formed in multiple parts. The first contact portions of each of the aforementioned first outer shell joints are connected to each other to form a whole.

77. The battery according to claim 1, characterized in that, The outermost part of the first connecting portion is separated from the innermost part of the rolled edge portion by a predetermined interval.

78. The battery according to claim 24, characterized in that, The angle between the first contact portion and the first connecting portion forms an acute angle through the first curved portion.

79. The battery according to claim 2, characterized in that, It has multiple of the above-mentioned injection holes.

80. The battery according to claim 79, characterized in that, The plurality of injection holes are arranged symmetrically about the center of the first electrode joint in the width direction.

81. The battery according to claim 80, characterized in that, Weld lines are formed between the injection holes arranged symmetrically on the left and right sides for joining the first tab joint and the first uncoated part.

82. The battery according to claim 2, characterized in that, The aforementioned first electrode lug joint is formed such that its width at a position separated by a predetermined distance from the end of the first electrode lug joint in the length direction of the connection portion of the first electrode lug joint and the support portion is greater than the width at the connection portion of the first electrode lug joint and the support portion.

83. The battery according to claim 82, characterized in that, The aforementioned injection hole is formed at a predetermined distance from the end of the connection portion along the length direction toward the first electrode joint portion.

84. The battery according to claim 83, characterized in that, At least a portion of the area where the injection hole is formed includes the area where the width increases at a predetermined distance from the end of the first electrode joint to the end of the first electrode joint, compared to the width at the connection between the first electrode joint and the support.

85. The battery according to claim 2, characterized in that, The end of the first tab joint in the length direction has an arc shape corresponding to the inner circumferential surface of the battery casing.

86. The battery according to claim 71, characterized in that, The extension direction of the welding pattern formed between the first uncoated portion and the first tab joint portion is perpendicular to the extension direction of the welding pattern formed between the rolled edge portion and the first contact portion.

87. The battery according to claim 51, characterized in that, In the radial direction, the innermost part of the rolled edge is positioned closer to the inside than the end part of the crimped part.

88. The battery according to claim 53, characterized in that, The aforementioned sealing gasket surrounds the aforementioned outer casing cover. The radial length of the portion of the sealing gasket that covers the lower surface of the outer casing is shorter than the radial length of the portion of the sealing gasket that covers the upper surface of the outer casing.

89. The battery according to claim 64, characterized in that, Let T be the total length in the radial direction of the aforementioned first electrode joint. Let the outer diameter of the above electrode assembly be JR. When the height of the segment plate disposed on the outermost contour of the above electrode assembly is set to F, the following formula is satisfied: JR–2 F≤T<JR。 90. The battery according to claim 1, characterized in that, The ratio of the area of ​​the first current collector that does not contact the upper surface of the electrode assembly to the area of ​​a circle with the outer diameter of the electrode assembly is 30% or more and less than 100%.

91. The battery according to claim 1, characterized in that, The ratio of the area of ​​the first current collector that does not contact the electrode assembly to the area of ​​a circle with the outer diameter of the electrode assembly is 60% or more and less than 100%.

92. The battery according to claim 33, characterized in that, The diameter of the current collector hole is smaller than the diameter of the winding hole provided in the core of the electrode assembly.

93. The battery according to claim 92, characterized in that, When the diameter of the aforementioned winding hole is set to R3, the diameter of the aforementioned current collector hole is 0.

5. R3 or higher and less than R3.

94. The battery according to claim 92, characterized in that, When the diameter of the aforementioned winding hole is set to R3, the diameter of the aforementioned current collector hole is 0.

7. R3 or higher and less than R3.

95. The battery according to claim 1, characterized in that, The ratio of the shape factor obtained by dividing the diameter of the battery by its height is greater than 0.

4.

96. The battery according to claim 1, characterized in that, The resistance measured between the anode and cathode is less than 4 mΩ.

97. A current collector for electrically connecting the electrode assembly and the battery casing of a battery according to any one of claims 1 to 95. The current collector is characterized in that it includes: A support portion is disposed on the upper part of the electrode assembly described above; Multiple tab joints extend from the aforementioned support portion and are joined to the first uncoated portion of the aforementioned electrode assembly; and The first housing joint extends from the aforementioned support portion and is located between adjacent aforementioned tab joint portions, and is electrically joined to the rolled edge portion of the aforementioned battery housing. The aforementioned tab connection and the aforementioned first outer shell connection are not directly connected, but are indirectly connected through the aforementioned support portion. The aforementioned first outer shell joint includes: The first contact portion is attached to the inner surface of the aforementioned battery casing; and The first connecting portion connects the aforementioned support portion and the aforementioned first contact portion.

98. The current collector according to claim 97, characterized in that, The aforementioned tab joint has at least one injection hole.

99. The current collector according to claim 97, characterized in that, The first connecting portion has at least one first curved portion, which changes its extension direction at least once.

100. The current collector according to claim 97, characterized in that, The aforementioned current collector has a current collector hole formed at its center.

101. The current collector according to claim 97, characterized in that, The current collector further includes a second housing connection portion, which extends from the end of one of the plurality of tab connections and is connected to the inner side of the battery housing.

102. The current collector according to claim 101, characterized in that, The aforementioned second outer shell joint includes: The second contact portion is attached to the inner side of the aforementioned battery casing; and The second connecting portion connects the end of one of the plurality of tab connecting portions to the second contact portion.

103. The current collector according to claim 97, characterized in that, It has multiple of the aforementioned first outer shell joints, The first contact portions of each of the aforementioned first outer shell joints are connected to each other to form a whole.

104. The current collector according to claim 99, characterized in that, The angle between the first contact portion and the first connecting portion forms an acute angle through the first curved portion.

105. The current collector according to claim 98, characterized in that, It has multiple of the above-mentioned injection holes.

106. The current collector according to claim 105, characterized in that, The aforementioned injection holes are arranged symmetrically on the left and right sides with reference to the center of the aforementioned tab joint in the width direction.

107. The current collector according to claim 98, characterized in that, Compared to the width at the connection between the aforementioned tab joint and the aforementioned support portion, the width of the aforementioned tab joint at a position separated by a predetermined distance from the end of the aforementioned connection portion in the length direction toward the aforementioned tab joint is greater.

108. The current collector according to claim 107, characterized in that, The aforementioned injection hole is located at a predetermined distance from the end of the connection portion along the length direction toward the tab joint portion.

109. The current collector according to claim 108, characterized in that, At least a portion of the area where the injection hole is formed includes the area where the width increases at a position that is a predetermined distance away from the end of the electrode joint compared to the width at the connection between the tab joint and the support.

110. The current collector according to claim 97, characterized in that, The end of the aforementioned tab joint in the longitudinal direction has an arc shape corresponding to the inner circumferential surface of the aforementioned battery casing.

111. A battery pack, characterized in that, It includes a plurality of batteries as described in any one of claims 1 to 96.

112. The battery pack according to claim 111, characterized in that, Multiple of the above batteries are arranged in a predetermined number of columns. The terminals of each battery and the outer surface of the bottom of the battery casing are arranged facing upwards.

113. The battery pack according to claim 112, characterized in that, It includes: Multiple buses connect multiple batteries in series and parallel. Each bus is configured on top of an adjacent battery. Each bus includes: The main body extends between adjacent terminals; A plurality of first bus terminals extend toward one side of the aforementioned main body and are electrically coupled to the electrode terminals of a battery located on that side; and Multiple second bus terminals extend to the other side of the main body and are electrically coupled to the outer surface of the bottom of the battery casing of the battery located on the other side.

114. A car, characterized in that, It includes the battery pack according to claim 111.

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