Electrode terminal fixing structure, and battery, battery pack and vehicle including the same

Abstract

To reduce internal resistance of a cylindrical battery and increase energy density by improving an electrode terminal structure of the cylindrical battery and increasing space efficiency in a battery housing.SOLUTION: Disclosed are an electrode terminal fixing structure, and a battery, a battery pack and a vehicle including the same. The electrode terminal fixing structure includes a battery housing having a bottom portion having one side opened and the other side formed with a through hole, an electrode terminal mounted through the through hole so as not to be in contact with an inner wall of the through hole, and a terminal gasket interposed between the electrode terminal and the through hole, wherein the electrode terminal includes a body portion inserted into the through hole, an outer flange portion extending from a first side of the body portion along an outer surface of the bottom portion of the battery housing, an inner flange portion extending from a second side of the body portion toward an inner surface of the bottom portion of the battery housing, and a flat portion provided inside the inner flange portion.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a fixing structure for an electrode terminal, and a battery, a battery pack, and an automobile including the same.

[0002] This application is a Korean Patent Application No. 10-2021-0007278 filed on January 19, 2021, Korean Patent Application No. 10-2021-0022897 filed on February 19, 2021, Korean Patent Application No. 10-2021-0022894 filed on February 19, 2021, Korean Patent Application No. 10-2021-0022891 filed on February 19, 2021, Korean Patent Application No. 10-2021-0022881 filed on February 23, 2021, Korean Patent Application No. 10-2021-0024424 filed on March 31, 2021 Korean Patent Application No. 10-2021-0030300 filed on March 8, 2021, Korean Patent Application No. 10-2021-0030291 filed on March 8, 2021, Korean Patent Application No. 10-2021-0046798 filed on April 9, 2021, Korean Patent Application No. 10-2021-0058183 filed on May 4, 2021, Korean Patent Application No. 10-2021-0077046 filed on June 14, 2021, Korean Patent Application No. 10-2021-0084326 filed on June 28, 2021, Korean Patent Application No. 10-2021-0084326 filed on October 1, 2021 10-2021-0131225, Korean Patent Application No. 10-2021-0131215 filed on October 1, 2021, Korean Patent Application No. 10-2021-0131205 filed on October 1, 2021, Korean Patent Application No. 10-2021-0131208 filed on October 1, 2021, Korean Patent Application No. 10-2021-0131207 filed on October 14, 2021, Korean Patent Application No. 10-2021-0137001 filed on October 15, 2021 137856, Korean Patent Application No. 10-2021-0142196 filed on October 22, 2021, Korean Patent Application No. 10-2021-0153472 filed on November 9, 2021, Korean Patent Application No. 10-2021-0160823 filed on November 19, 2021, Korean Patent Application No. 10-2021-0163809 filed on November 24, 2021, Korean Patent Application No. 10-2021-0165866 filed on November 26, 2021, Korean Patent Application No. 10-2021-0172446 filed on December 3, 2021,Korean Patent Application No. 10-2021-0177091 filed on December 10, 2021, Korean Patent Application No. 10-2021-0194593 filed on December 31, 2021, Korean Patent Application No. 10-2021-0194610 filed on December 31, 2021, Korean Patent Application No. 10-2021-0194572 filed on December 31, 2021, Priority is claimed based on Korean Patent Application No. 10-2021-0194612 filed on December 31, 2021, Korean Patent Application No. 10-2021-0194611 filed on December 31, 2021, and Korean Patent Application No. 10-2022-0001802 filed on January 5, 2022, and the contents disclosed in the specifications and drawings of those applications are incorporated herein in their entirety. [Background technology]

[0003] Secondary batteries, which have high applicability to each product group and electrical properties such as high energy density, are widely used not only in portable devices but also in electric vehicles (EVs) and hybrid electric vehicles (HEVs) that are driven by electrical sources.

[0004] These secondary batteries not only have the primary advantage of dramatically reducing the use of fossil fuels, but are also environmentally friendly as they do not produce any by-products from energy use, and are attracting attention as a new energy source for improving energy efficiency.

[0005] Currently, secondary batteries such as lithium-ion batteries, lithium polymer batteries, nickel-cadmium batteries, nickel-metal hydride batteries, and nickel-zinc batteries are widely used. The operating voltage of such unit secondary batteries is approximately 2.5V to 4.5V. Therefore, when a higher output voltage is required, a battery pack is constructed by connecting multiple batteries in series. Alternatively, a battery pack may be constructed by connecting multiple batteries in parallel depending on the required charge / discharge capacity of the battery pack. Therefore, the number of batteries included in the battery pack and the electrical connection configuration can be variously set depending on the required output voltage and / or charge / discharge capacity.

[0006] Meanwhile, known types of secondary batteries include cylindrical, prismatic, and pouch-type batteries. In the case of cylindrical batteries, a separator, which is an insulator, is interposed between a positive electrode and a negative electrode, and the separator is wound up to form a jelly-roll-type electrode assembly. This is then inserted into a battery housing together with an electrolyte to form a battery. Strip-shaped electrode tabs are connected to the uncoated portions of the positive and negative electrodes, and the electrode tabs electrically connect the electrode assembly to electrode terminals exposed to the outside. For reference, the positive electrode terminal is a sealed cap that seals the opening of the battery housing, and the negative electrode terminal is the battery housing.

[0007] However, conventional cylindrical batteries having such a structure have problems such as high resistance, excessive heat generation, and poor current collection efficiency because current is concentrated in the strip-shaped electrode tabs connected to the positive electrode uncoated region and / or the negative electrode uncoated region.

[0008] Resistance and heat generation are not a major issue for small cylindrical batteries with form factors such as 1865 (diameter: 16mm, height: 65mm) and 2170 (diameter: 21mm, height: 70mm). However, when the form factor of cylindrical batteries is increased to be used in electric vehicles, a large amount of heat is generated around the electrode tabs during the fast charging process, which can cause the cylindrical battery to catch fire.

[0009] To solve these problems, a cylindrical battery (so-called tab-less cylindrical battery) has been proposed, which has a structure in which positive and negative electrode uncoated areas are located at the top and bottom of a jelly-roll type electrode assembly, respectively, and current collectors are welded to these uncoated areas to improve current collection efficiency.

[0010] Figures 1 to 3 show the manufacturing process of a tabless cylindrical battery. Figure 1 shows the structure of the electrode, Figure 2 shows the electrode winding process, and Figure 3 shows the process of welding a current collector to the folded surface of the uncoated portion. Figure 4 is a cross-sectional view of the tabless cylindrical battery cut along the longitudinal direction (Y-axis direction).

[0011] 1 to 4, the positive electrode 10 and the negative electrode 11 have a structure in which an active material 21 is coated on a sheet-shaped current collector 20, and include a plain portion 22 on one long side along the winding direction X.

[0012] The electrode assembly A is fabricated by sequentially stacking a positive electrode 10 and a negative electrode 11 together with two separators 12, as shown in Figure 2, and then winding the stack in one direction (X-axis direction). At this time, the uncoated portion of the positive electrode 10 and the uncoated portion of the negative electrode 11 are arranged in opposite directions.

[0013] After the winding process, the uncoated portion 10a of the positive electrode 10 and the uncoated portion 11a of the negative electrode 11 are folded toward the core. Thereafter, the current collectors 30 and 31 are welded and joined to the uncoated portions 10a and 11a, respectively.

[0014] No separate electrode tabs are attached to the positive electrode uncoated region 10a and the negative electrode uncoated region 11a, and current collectors 30 and 31 are connected to external electrode terminals, forming a current path with a large cross-sectional area along the winding axis direction of electrode assembly A (see arrow), which has the advantage of reducing battery resistance, since resistance is inversely proportional to the cross-sectional area of ​​the path through which current flows.

[0015] However, as the form factor of cylindrical batteries increases and the charging current during fast charging increases, the heat generation problem reoccurs even in tableless cylindrical batteries.

[0016] Specifically, as shown in Figure 4, a conventional tabless cylindrical battery 40 includes a battery housing 41 and a sealing body 42. The battery housing 41 is also called a battery can. The sealing body 42 includes a cap 42a, a sealing gasket 42b, and a connecting plate 42c. The sealing gasket 42b encloses the periphery of the cap 42a and is secured in place by a crimping portion 43. The electrode assembly A is secured within the battery housing 41 by a beading portion 44 to prevent vertical movement.

[0017] Typically, the positive electrode terminal is the cap 42a of the sealing body 42, and the negative electrode terminal is the battery housing 41. Therefore, the current collector 30 attached to the uncoated portion 10a of the positive electrode 10 is electrically connected to a connecting plate 42c attached to the cap 42a via a strip-shaped lead 45. Also, the current collector 31 attached to the uncoated portion 11a of the negative electrode 11 is electrically connected to the bottom of the battery housing 41. An insulator 46 covers the current collector 30 to prevent contact between the battery housing 41 and the uncoated portion 10a of the positive electrode 10, which have opposite polarities, and causing a short circuit.

[0018] When the current collector 30 is connected to the connecting plate 42c, a strip-shaped lead 45 is used. The lead 45 is either separately attached to the current collector 30 or integrally manufactured with the current collector 30. However, because the lead 45 is a thin strip, its cross-sectional area is small, and a large amount of heat is generated when a fast charging current flows. In addition, the excessive heat generated in the lead 45 is transferred to the electrode assembly A, causing the separator 12 to contract, which can lead to an internal short circuit, a major cause of thermal runaway.

[0019] Furthermore, the leads 45 occupy a considerable amount of installation space within the battery housing 41. Therefore, the cylindrical battery 40 including the leads 45 has low space efficiency and is limited in increasing energy density.

[0020] In addition, the upper end of the crimping portion 43 has a negative polarity but a small area. Although the crimping portion 43 is shown large in the drawings, in reality, the upper end of the crimping portion 43 has a much smaller area than the sealing body 42. Therefore, in order to stably connect the busbar parts, the only way is to connect the positive electrode to the sealing body 42 crimped to the open end of the battery housing 41 and connect the negative electrode to the bottom of the battery housing 41.

[0021] In order to connect conventional table-less cylindrical batteries 40 in series and / or parallel, busbar components must be connected to the cap 42a of the sealed body 42 and the bottom of the battery housing 41, resulting in reduced space efficiency. A battery pack installed in an electric vehicle includes hundreds of cylindrical batteries 40. Therefore, inefficiencies in electrical wiring cause considerable inconvenience during the electric vehicle assembly process and battery pack maintenance. Summary of the Invention [Problem to be solved by the invention]

[0022] The present invention was made in light of the background of the prior art described above, and aims to improve the electrode terminal structure of a cylindrical battery to increase the space efficiency within the battery housing, thereby reducing the internal resistance of the cylindrical battery and increasing the energy density.

[0023] Another object of the present invention is to improve the electrode terminal structure of a cylindrical battery to increase the cross-sectional area of ​​the current path, thereby alleviating the problem of internal heat generation that occurs during fast charging.

[0024] Another object of the present invention is to provide a cylindrical battery with an improved structure in which electrical wiring for series and / or parallel connection of cylindrical batteries can be performed on only one side of the cylindrical battery.

[0025] It is yet another object of the present invention to provide a battery pack manufactured using a cylindrical battery having an improved structure, and a vehicle including the same.

[0026] The technical problems to be solved by the present invention are not limited to the above-mentioned problems, and other problems will be clearly understood by those skilled in the art from the following description of the invention. [Means for solving the problem]

[0027] To achieve the above object, the electrode terminal fixing structure according to the present invention includes a battery housing having a bottom portion with one side open and the other side formed with a through hole; an electrode terminal attached by passing through the through hole so as not to come into contact with the inner wall of the through hole; and a terminal gasket interposed between the electrode terminal and the through hole, wherein the electrode terminal includes a body portion inserted into the through hole, an outer flange portion extending from a first side of the body portion along an outer surface of a bottom of the battery housing, an inner flange portion extending from a second side of the body portion toward an inner surface of the bottom of the battery housing, and a flat portion provided on the inside of the inner flange portion.

[0028] Preferably, the flat portion and the inner surface of the bottom portion may be parallel to each other.

[0029] Preferably, the electrode terminal is made of metal, and the inner flange portion is formed by plastic working the first side of the main body portion.

[0030] In one embodiment, the electrode terminal may be a rivet terminal riveted through the through hole by the inner flange portion.

[0031] In another embodiment, the angle between the surface of the inner flange portion facing the bottom of the battery housing and the inner surface of the bottom of the battery housing may be 0° to 60°.

[0032] In yet another embodiment, the internal flange portion may include a first section that gradually becomes farther away from the bottom of the battery housing, and a second section that is connected to the first section and extends toward the bottom of the battery housing, and an angle between a surface of the second section facing the bottom and an inner surface of the bottom may be 0° to 30°.

[0033] Preferably, a recess may be provided between the inner flange and the flat portion.

[0034] In one embodiment, the recessed portion may be a closed-loop groove recessed in the central axis direction of the main body portion.

[0035] In another aspect, the recessed portion may have an asymmetric cross section.

[0036] In yet another embodiment, the asymmetric cross section may include a sidewall of the flat portion and a sloped surface of the inner flange portion connected to an end of the sidewall.

[0037] In yet another embodiment, the sidewalls may be perpendicular to the inner surface of the base.

[0038] In yet another embodiment, the sidewalls may be sloped toward the flat portion.

[0039] Preferably, the thickness of the inner flange portion decreases with increasing distance from the body portion.

[0040] Preferably, the terminal gasket may include an outer gasket interposed between the outer flange portion and a first plane on which the outer surface of the bottom of the battery housing is located, an inner gasket interposed between the inner flange portion and a second plane on which the inner surface of the bottom of the battery housing is located, and an intermediate gasket interposed between the main body portion and the through hole to connect the outer gasket and the inner gasket.

[0041] In one embodiment, the intermediate gasket may have a thickness that varies depending on the location.

[0042] In another aspect, the terminal gasket may have a minimum thickness at the intermediate gasket.

[0043] In yet another embodiment, the thickness of the region of the intermediate gasket adjacent to the first plane may increase as it approaches the first plane.

[0044] In yet another embodiment, the thickness of the region of the intermediate gasket adjacent to the second plane may increase as it approaches the second plane.

[0045] In yet another embodiment, a central region of the intermediate gasket located between the first and second planar surfaces may have a uniform thickness.

[0046] In yet another embodiment, the thickness of the region of the intermediate gasket interposed between the inner edge of the through hole connected to the inner surface of the bottom and the internal flange portion may be relatively smaller than the thickness of other regions of the intermediate gasket.

[0047] In yet another aspect, the intermediate gasket may have a thickness that gradually decreases in a direction away from the outer flange portion.

[0048] In yet another embodiment, the thickness of the inner gasket may be thinnest in a region between the inner surface of the bottom portion and the vicinity of the end of the inner flange portion.

[0049] In yet another embodiment, the inner edge of the through hole may include a facing surface that faces the inner flange portion.

[0050] In yet another embodiment, the internal gasket may extend beyond the internal flange portion to expose an end thereof.

[0051] In yet another embodiment, the height of the flat portion relative to the inner surface of the bottom portion may be equal to or greater than the height of the edge of the inner gasket.

[0052] In yet another embodiment, the height of the flat portion relative to the inner surface of the bottom may be the same as or greater than the height of the inner flange portion.

[0053] In yet another embodiment, the height of the inner flange portion relative to the inner surface of the bottom portion may be greater than the height of the inner gasket end portion.

[0054] Preferably, the height of the inner flange portion may be 0.5 mm to 3.0 mm based on the inner surface of the bottom of the battery housing.

[0055] Preferably, the height of the electrode terminal from the lower surface of the outer flange portion to the surface of the flat portion may be 4 mm to 7 mm.

[0056] Preferably, the height of the outer flange portion based on the outer surface of the bottom of the battery housing may be 0.8 mm or more.

[0057] Preferably, at least a portion of the outer gasket is exposed to the outside of the outer flange portion, and the exposed width of the outer gasket measured in a direction parallel to the outer surface of the bottom of the battery housing may be 0.1 mm to 1 mm.

[0058] Preferably, the radius from the center of the main body to the end of the outer flange may be 10% to 70% of the radius of the bottom of the battery housing.

[0059] Preferably, the radius from the center of the main body to the end of the flat portion may be 4% to 30% of the radius of the bottom portion.

[0060] Preferably, when the compression ratio is defined as the ratio of the thickness change amount at the maximum compression point to the thickness of the gasket before compression, the compression ratio of the terminal gasket may be 30% to 90%.

[0061] More preferably, the terminal gasket includes polybutylene terephthalate, polyfluoroethylene, or polypropylene, and the compression rate of the terminal gasket may be 50% to 90%.

[0062] Preferably, the thickness of the intermediate gasket of the terminal gasket before compression is substantially the same as the thickness of the inner gasket before compression, and the compressibility of the intermediate gasket and the inner gasket may be 50% to 90%.

[0063] To achieve the above object, the battery according to the present invention includes an electrode assembly in which a first electrode and a second electrode are wound with a separator interposed therebetween, and the electrode assembly includes a first portion of the first electrode and a second portion of the second electrode extending from both ends and exposed to the outside of the separator; a cylindrical battery housing that houses the electrode assembly and is electrically connected to the first electrode; an electrode terminal that is attached through a through hole formed in the bottom of the battery housing so as not to come into contact with the inner wall of the through hole and is electrically connected to the second electrode, the electrode terminal including a body portion inserted into the through hole, an outer flange portion extending from a first side of the body portion along the outer surface of the bottom of the battery housing, an inner flange portion extending from a second side of the body portion toward the inner surface of the bottom of the battery housing, and a flat portion provided inside the inner flange portion; a terminal gasket interposed between the electrode terminal and the through hole; and a sealing body that seals the open end of the battery housing so as to be insulative from the battery housing.

[0064] In one embodiment, the battery housing may include a beading portion pressed into the inside of the battery housing in a region adjacent to the open end, and the sealing body may include a non-polarized cap and a sealing gasket interposed between the periphery of the cap and the open end of the battery housing.

[0065] In another embodiment, the battery housing may further include a crimping portion that is extended and bent inward of the battery housing to enclose and fix the periphery of the cap together with the sealing gasket.

[0066] Preferably, the cap may include a venting notch that ruptures when the internal pressure of the battery housing exceeds a critical value.

[0067] Preferably, the venting notch is formed so that the internal pressure of the battery housing is 15 to 35 kgf / cm 2 It may burst when

[0068] In yet another aspect, the battery according to the present invention further includes a first current collector coupled to the first portion of the first electrode, and at least a portion of an end of the first current collector that does not contact the first portion of the first electrode may be interposed between the beading portion and the sealing gasket and fixed by the crimping portion.

[0069] Preferably, at least a portion of the end of the first current collector may be fixed to an inner circumferential surface of the beading portion adjacent to the crimping portion by welding.

[0070] In yet another embodiment, the battery according to the present invention further includes a second current collector coupled to a second portion of the second electrode, and at least a portion of the second current collector may be coupled to a flat portion of the electrode terminal.

[0071] Preferably, the second current collector and the flat portion of the electrode terminal are joined by welding, and a tensile strength of the weld between the second current collector and the flat portion of the electrode terminal may be 2 kgf or more.

[0072] Preferably, the equivalent diameter of the weld pattern exposed on the surface of the second current collector may be 2 mm or more.

[0073] Preferably, the diameter of the flat portion of the electrode terminal may be 3 mm to 14 mm.

[0074] Preferably, the ratio of the area of ​​the welding pattern exposed on the surface of the second current collector to the area of ​​the flat portion of the electrode terminal may be 2.04% to 44.4%.

[0075] In yet another embodiment, the battery according to the present invention may further include an insulator interposed between the second current collector and an inner surface of the bottom of the battery housing, and between an inner peripheral surface of the side wall of the battery housing and the electrode assembly.

[0076] Preferably, the insulator may include a welding hole that exposes the flat portion of the electrode terminal to the second current collector, and may cover a surface of the second current collector and one side end of the electrode assembly.

[0077] Preferably, the height from the inner surface of the bottom of the battery housing to the flat portion of the electrode terminal may be equal to or smaller than the thickness of the insulator.

[0078] Preferably, the terminal gasket may include an outer gasket interposed between the outer flange portion and a first plane on which the outer surface of the bottom of the battery housing is located, an inner gasket interposed between the inner flange portion and a second plane on which the inner surface of the bottom of the battery housing is located, and an intermediate gasket interposed between the main body portion and the through hole to connect the outer gasket and the inner gasket.

[0079] Preferably, an end of the inner gasket may be exposed to the outside of the inner flange portion.

[0080] In yet another embodiment, the weld hole may expose a flat portion and an inner flange portion of the electrode terminal.

[0081] In yet another embodiment, the weld hole may expose a flat portion and an inner flange portion of the electrode terminal and the inner gasket.

[0082] In yet another embodiment, the battery according to the present invention may have a first bus bar terminal electrically coupled to a surface of the electrode terminal, and a second bus bar terminal electrically coupled to an outer surface of the bottom of the battery housing.

[0083] Preferably, the first bus bar terminals overlap the electrode terminals in a plane to form a first overlapping region, and the second bus bar terminals overlap the outer surface of the bottom of the battery housing in a plane to form a second overlapping region, and a diameter of the electrode terminals and a width of the outer surface of the bottom of the battery housing may satisfy the following Equation 1: [Formula 1] W1≦E1≦D-2R d -2G-2W2 E2=0.5×(D-2R d -2G-E1) (E1: diameter of electrode terminal, E2: width of exposed surface of bottom of battery housing parallel to the surface of electrode terminal, D: outer diameter of battery housing, R d : width of the rounded area on the periphery of the battery housing measured on a flat surface, G: exposed width of the outer gasket through the periphery of the electrode terminal, W1: maximum value between any two points selected at the edge of the first overlapping area, W2: maximum value of the distance between two points where multiple lines passing through the center of the electrode terminal intersect with the edge of the second overlapping area)

[0084] In yet another embodiment, the battery's form factor ratio of diameter divided by height may be greater than 0.4.

[0085] The above object is achieved by a battery pack including a plurality of the above-described batteries.

[0086] Preferably, the plurality of batteries are arranged in a predetermined number of rows; The electrode terminals of each battery and the outer surface of the bottom of the battery housing may be arranged facing upward.

[0087] Preferably, the battery pack according to the present invention includes a plurality of bus bars connecting a plurality of batteries in series and in parallel, the plurality of bus bars being disposed on top of the plurality of batteries, and each of the plurality of bus bars may include a body portion extending between electrode terminals of adjacent batteries, a plurality of first bus bar terminals extending to one side of the body portion and electrically coupled to the electrode terminals of the batteries located on that side, and a plurality of second bus bar terminals extending to the other side of the body portion and electrically coupled to an outer surface of a bottom of a battery housing of the batteries located on the other side.

[0088] Preferably, the AC resistance measured between the electrode terminals of the battery and the outer surface of the bottom of the battery housing may be 0.5 mΩ to 4 mΩ, preferably 1 mΩ to 4 mΩ.

[0089] The above objectives are achieved by a vehicle including the battery pack described above. [Effects of the Invention]

[0090] According to one aspect of the present invention, the electrode terminal structure of a battery is improved to increase space efficiency within a battery housing, thereby reducing the internal resistance of the battery and increasing the energy density.

[0091] According to another aspect of the present invention, the problem of internal heat generation occurring during rapid charging can be alleviated by improving the electrode terminal structure of the battery to increase the cross-sectional area of ​​the current path.

[0092] According to yet another aspect of the present invention, electrical wiring for connecting batteries in series and / or in parallel can be performed on only one side of the battery.

[0093] According to yet another aspect of the present invention, a battery pack manufactured using a battery having an improved structure and a vehicle including the same can be provided.

[0094] The following drawings attached to this specification illustrate preferred embodiments of the present invention and, together with the detailed description of the invention, serve to further understand the technical concepts of the present invention. Therefore, the present invention should not be interpreted as being limited to only the matters described in the drawings. [Brief explanation of the drawings]

[0095] [Figure 1] 1 is a plan view showing the structure of an electrode used in a conventional tabless cylindrical battery. [Figure 2] 1A and 1B are diagrams illustrating a winding process of an electrode assembly included in a conventional tabless cylindrical battery. [Figure 3] 3 is a view showing a process of welding a current collector to a bent surface of an uncoated portion in the electrode assembly of FIG. 2. FIG. [Figure 4] FIG. 1 is a cross-sectional view of a conventional tablets cylindrical battery cut in the longitudinal direction (Y-axis direction). [Figure 5] 1 is a cross-sectional view showing a fixing structure of an electrode terminal according to an embodiment of the present invention. [Figure 6a] FIG. 6 is an enlarged cross-sectional view of a portion indicated by a dotted circle in FIG. 5. [Figure 6b] FIG. 10 is a partially enlarged cross-sectional view showing a fixing structure for an electrode terminal according to another embodiment of the present invention. [Figure 6c] 3 is a plan view schematically showing a welding pattern formed on a flat portion of an electrode terminal according to an embodiment of the present invention. FIG. [Figure 7a] 1 is a cross-sectional view of a cylindrical battery according to an embodiment of the present invention taken along the longitudinal direction (Y-axis direction). [Figure 7b] 4 is a cross-sectional view of a cylindrical battery according to another embodiment of the present invention, taken along the longitudinal direction (Y-axis direction). FIG. [Figure 8] 1 is a plan view illustrating an example of an electrode structure according to a preferred embodiment of the present invention. [Figure 9] 1 is a cross-sectional view of an electrode assembly in which a plain partial cut structure of an electrode according to an embodiment of the present invention is applied to first and second electrodes, taken along a longitudinal direction (Y-axis direction). [Figure 10a] 1 is a cross-sectional view of an electrode assembly in which an uncoated portion is bent according to an embodiment of the present invention, taken along a longitudinal direction (Y-axis direction). [Figure 10b] 1 is a perspective view of an electrode assembly in which a non-coating portion is folded according to an embodiment of the present invention; [Figure 11] 1 is a top plan view illustrating a state in which a plurality of cylindrical batteries are connected in series and parallel using bus bars according to an embodiment of the present invention. FIG. [Figure 12a] FIG. 12 is an enlarged view of a part of FIG. [Figure 12b] FIG. 10 is a diagram illustrating exemplary parameters used to define the diameter of an electrode terminal and the exposed width of the outer surface of the bottom of a battery housing according to an embodiment of the present invention. [Figure 12c] FIG. 10 is a diagram illustrating exemplary parameters used to define the diameter of an electrode terminal and the exposed width of the outer surface of the bottom of a battery housing according to an embodiment of the present invention. [Figure 13] 1 is a diagram illustrating a schematic configuration of a battery pack including a cylindrical battery according to an embodiment of the present invention. [Figure 14] 1 is a diagram showing a schematic configuration of a vehicle including a battery pack according to an embodiment of the present invention; DETAILED DESCRIPTION OF THE INVENTION

[0096] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Prior to this, the terms and words used in the specification and claims should not be interpreted as being limited to their ordinary and dictionary meanings, but should be interpreted as having meanings and concepts corresponding to the technical ideas of the present invention, in accordance with the principle that the inventors themselves can appropriately define the concepts of terms in order to best explain the invention.

[0097] Therefore, it should be understood that the embodiments described in this specification and the configurations shown in the drawings are merely the most preferred embodiment of the present invention and do not represent the entire technical idea of ​​the present invention, and that there may be various equivalents and modifications that can be substituted for them at the time of this application.

[0098] In order to facilitate understanding of the invention, the accompanying drawings may not be drawn to scale, and the dimensions of some components may be exaggerated. In addition, the same reference numerals may be used to refer to the same components in different embodiments.

[0099] The expression that two comparison objects are identical means that they are "substantially identical." Therefore, "substantially identical" may include deviations that are considered low in the art, for example, deviations within 5%. Furthermore, the expression that a parameter is uniform in a given region means that the parameter is uniform on average in that region.

[0100] Furthermore, although terms such as "first" and "second" are used to indicate various components, these terms are not intended to limit the components. These terms are used merely to distinguish one component from another, and unless otherwise specified, the first component can also be the second component.

[0101] Throughout the specification, unless otherwise stated, each element may be singular or plural.

[0102] When an arbitrary structure is placed "on (or under)" a component or "above (or below)" a component, it means not only that the arbitrary structure is placed in contact with the upper surface (or lower surface) of the component, but also that other structures may be interposed between the component and the arbitrary structure placed above (or below) the component.

[0103] Furthermore, when a component is said to be "coupled," "coupled," or "connected" to another component, it does not only mean that the components are directly coupled or connected to each other, but also that other components are "intervening" between the components, or that each component is "coupled," "coupled," or "connected" through other components.

[0104] Throughout the specification, unless otherwise specified, "A and / or B" means A, B, or A and B, and "C to D" means C or more and D or less, unless otherwise specified.

[0105] For ease of explanation, in this specification, the direction along the longitudinal direction of the winding shaft of the electrode assembly wound into a jelly roll is referred to as the axial direction (Y-axis direction). The direction surrounding the winding shaft is referred to as the circumferential direction or outer circumferential direction (X-axis direction). The direction approaching or moving away from the winding shaft is referred to as the radial direction. Of these, the direction approaching the winding shaft is referred to as the centripetal direction, and the direction moving away from the winding shaft is referred to as the centrifugal direction.

[0106] A cylindrical battery according to an embodiment of the present invention includes electrode terminals attached to through-holes formed in the bottom of a battery housing.

[0107] FIG. 5 is a cross-sectional view showing a fixing structure of an electrode terminal 50 according to an embodiment of the present invention, and FIG. 6a is an enlarged cross-sectional view of a portion circled by a dotted line in FIG.

[0108] 5 and 6a, the electrode terminal 50 includes a body 50a including an upper surface, a lower surface, and an outer surface, an outer flange 50b extending from the outer surface of the body 50a along the outer surface 52a of the bottom 52 of the battery housing 51, and an inner flange 50c extending from the outer surface of the body 50a toward the inner surface 52b of the bottom 52 of the battery housing 51. The upper surface of the body 50a is flat and can be connected to a current collector, and is located above the inner flange 50c.

[0109] The fixing structure for the electrode terminal 50 according to the embodiment of the present invention can be applied to a cylindrical battery housing 51. Specifically, the fixing structure for the electrode terminal 50 includes a battery housing 51 having one open side, an electrode terminal 50 fixed through a through-hole 53 formed in a bottom 52 of the battery housing 51, and a terminal gasket 54 interposed between the electrode terminal 50 and the through-hole 53.

[0110] The battery housing 51 may include a cylindrical side wall and a bottom 52 connected to an end of the side wall. A through hole 53 is formed in the bottom 52, so that the battery housing 51 has a structure in which one side is open and the other side is partially closed by the bottom 52. The battery housing 51 may have other shapes besides a cylindrical shape, for example, a rectangular shape having a square cross section.

[0111] The battery housing 51 is made of a conductive metal material. For example, the battery housing 51 may be made of a steel material, but the present invention is not limited thereto. The inner and outer surfaces of the battery housing 51 may be coated with a Ni plating layer.

[0112] The electrode terminal 50 is made of a conductive metal material. For example, the electrode terminal 50 may be made of aluminum, but the present invention is not limited to this. The electrode terminal 50 may be made of a 10-series aluminum alloy, which is easy to plastically process and has low resistance. Plastic processing is a method of applying physical force to metal to deform it into a desired shape, and may include riveting, caulking, etc.

[0113] The terminal gasket 54 may be made of an insulating and elastic polymer resin. For example, the terminal gasket 54 may be made of polypropylene, polybutylene terephthalate, polyethylene fluoride, etc., but the present invention is not limited thereto.

[0114] Preferably, the electrode terminal 50 is attached to the through-hole 53 so as not to come into contact with the inner wall of the through-hole 53 .

[0115] The electrode terminal 50 includes a body portion 50a inserted into the through-hole 53. The body portion 50a may include an upper surface, a lower surface, and an outer surface connecting the upper surface, lower surface, and lower surface. The electrode terminal 50 may also include an outer flange portion 50b extending from the outer periphery of a first side of the body portion 50a exposed from the outer surface 52a of the bottom 52 of the battery housing 51 along the outer surface 52a, an inner flange portion 50c extending from the outer periphery of a second side of the body portion 50a exposed from the inner surface 52b of the bottom 52 of the battery housing 51 toward the inner surface 52b, and a flat portion 50d provided inside the inner flange portion 50c and surrounded by the inner flange portion 50c.

[0116] Desirably, the flat portion 50d corresponds to the upper surface of the main body portion 50a. The flat portion 50d and the inner surface 52b of the bottom portion 52 of the battery housing 51 may be parallel. Here, "parallel" means that they are substantially parallel when observed visually. The flat portion 50d may be a surface that was already formed before the electrode terminal 50 was subjected to plastic working. In other words, the flat portion 50d may be a region that is not deformed by plastic working.

[0117] Preferably, the electrode terminal 50 is made of metal, and the inner flange portion 50c may be formed by plastically processing the upper outer edge of the body portion 50a. The plastic processing may be caulking, but the present invention is not limited thereto. In one embodiment, the electrode terminal 50 may be a rivet terminal riveted through the through-hole 53 by the inner flange portion 50c.

[0118] The inner flange portion 50c extends in a direction gradually moving away from the bottom portion 52 of the battery housing 51. The angle (θ) between the surface of the inner flange portion 50c facing the bottom portion 52 of the battery housing 51 and the inner surface 52b of the bottom portion 52 of the battery housing 51 may be 0° to 60°.

[0119] The magnitude of the angle (θ) is determined by the strength of the crimping process when the electrode terminal 50 is attached to the through-hole 53 of the battery housing 51. For example, as the crimping strength increases, the angle (θ) may decrease to 0°. If the angle (θ) exceeds 60°, the sealing effect of the terminal gasket 54 may be reduced.

[0120] On the other hand, since the outer flange portion 50b is substantially parallel to the bottom portion 52 of the battery housing 51, the angle between the inner flange portion 50c and the outer flange portion 50b can also be 0° to 60°.

[0121] According to another embodiment, a recess 55 may be provided between the inner flange portion 50c and the flat portion 50d. The recess 55 is a groove recessed in the central axis direction of the main body portion 50a. The groove may have a closed loop shape when viewed along the central axis direction of the main body portion 50a. The recess 55 may have an asymmetric cross-section. For example, the asymmetric cross-section may be substantially V-shaped or U-shaped. The asymmetric cross-section may include a sidewall 55a of the flat portion 50d and an inclined surface 55b connected to the end of the sidewall 55a and formed by the upper surface of the inner flange portion 50c. The outer surface of the main body portion 50a exposed from the sidewall 55a may be referred to as a first surface, and the inclined surface 55b may be referred to as a second surface. The first surface and the second surface are asymmetric. The sidewall 55a may be substantially perpendicular to the inner surface 52b of the bottom 52 of the battery housing 51. "Perpendicular" means substantially perpendicular when observed visually. As will be described later, the side wall 55a may be inclined toward the flat portion 50d. The recessed portion 55 is formed according to the shape of a crimping jig used when the electrode terminal 50 is attached to the through-hole 53 of the battery housing 51 by crimping.

[0122] Preferably, the thickness of the inner flange portion 50c may decrease as it becomes farther from the main body portion 50a of the electrode terminal 50.

[0123] According to another embodiment, the terminal gasket 54 may include an external gasket 54a interposed between the external flange portion 50b and a first plane P1 on which the outer surface 52a of the bottom 52 of the battery housing 51 is located, an internal gasket 54b interposed between the internal flange portion 50c and a second plane P2 on which the inner surface 52b of the bottom 52 of the battery housing 51 is located, and an intermediate gasket 54c interposed between the main body portion 50a and the through hole 53, connecting the external gasket 54a and the internal gasket 54b.

[0124] The outer gasket 54a and / or the inner gasket 54b and / or the middle gasket 54c may have a thickness that varies depending on the location.

[0125] Desirably, the intermediate gasket 54c may have a thickness that varies with location, and the terminal gasket 54 may have a minimum thickness at the intermediate gasket 54c.

[0126] In one embodiment, the thickness of the region of the intermediate gasket 54c adjacent to the first plane P1 may increase as it approaches the first plane P1. Similarly, the thickness of the region of the intermediate gasket 54c adjacent to the second plane P2 may increase as it approaches the second plane P2. Furthermore, the thickness of the central region of the intermediate gasket 54c located between the first plane P1 and the second plane P2 may be uniform.

[0127] Preferably, the thickness of the intermediate gasket 54c in a region between the inner flange 50c and the inner edge 56 of the through hole 53 connected to the inner surface 52b of the bottom 52 of the battery housing 51 may be relatively small. Preferably, a point of minimum thickness may be present in the region of the intermediate gasket 54c interposed between the inner edge 56 of the through hole 53 and the inner flange 50c. In addition, the inner edge 56 of the through hole 53 may include an opposing surface 57 facing the inner flange 50c.

[0128] Meanwhile, the upper and lower ends of the inner wall of the through hole 53, which are perpendicular to the bottom 52 of the battery housing 51, are chamfered (corner cut) to form a tapered surface toward the electrode terminal 50. However, the upper and / or lower ends of the inner wall of the through hole 53 may be deformed into a smooth curved surface. In this case, the stress applied to the gasket 54 near the upper and / or lower ends of the inner wall of the through hole 53 can be further alleviated.

[0129] Preferably, the inner gasket 54b may form an angle (θ) of 0° to 60° with the inner surface 52b of the bottom 52 of the battery housing 51 and extend longer than the inner flange portion 50c.

[0130] In yet another embodiment, the height (H1) of the flat portion 50d, measured from the inner surface 52b of the bottom 52 of the battery housing 51, may be the same as or greater than the height (H2) of the end of the internal gasket 54b. Furthermore, the height (H1) of the flat portion 50d, measured from the inner surface 52b of the bottom 52 of the battery housing 51, may be the same as or greater than the height (H3) of the end of the internal flange portion 50c. Here, the height H2 is the maximum height of the end of the internal gasket 54b measured from the inner surface 52b. Furthermore, the height H3 is the maximum height of the top surface of the internal flange portion 50c measured from the inner surface 52b.

[0131] When the height parameters H1, H2, and H3 satisfy the above conditions, the inner flange portion 50c and the inner gasket 54b can be prevented from interfering with other components.

[0132] Preferably, the height (H3) of the inner flange portion 50c is 0.5 mm to 3.0 mm. If the height (H3) of the inner flange portion 50c is less than 0.5 mm, sufficient sealing performance cannot be ensured. Also, if the height (H3) of the inner flange portion 50c is more than 3 mm, the internal space of the battery housing 51 that can be occupied by the electrode assembly is reduced.

[0133] Preferably, the height (H4) of the electrode terminal 50 is 1.5 mm to 7 mm. The height (H4) of the electrode terminal 50 corresponds to the distance from the lower surface of the outer flange portion 50b to the flat portion 50d. If the height (H4) of the electrode terminal 50 is less than 1.5 mm, it is difficult to increase the height of the inner flange portion 50c to a level that ensures sealing performance due to the thickness of the bottom portion 52 of the battery housing 51. For reference, the thickness of the bottom portion 52 of the battery housing 51 is approximately 0.5 mm to 1 mm. Also, if the height (H4) of the electrode terminal 50 exceeds 7 mm, the internal space of the battery housing 51 that can be occupied by the electrode assembly is reduced, increasing the height of the battery and correspondingly reducing the energy density per unit volume. If H3 and H4 satisfy the above numerical ranges, sufficient sealing performance of the electrode terminal 50 can be ensured without reducing the internal space of the battery housing 51.

[0134] In another embodiment, the height (H5) of the external flange portion 50b from the outer surface 52a of the bottom 52 of the battery housing 51 may be 0.8 mm or more. If the height (H5) of the external flange portion 50b is less than 0.8 mm, the external flange portion 50b may be deformed when the electrode terminal 50 is riveted. The thickness of the external gasket 54a is 0.3 mm or more in consideration of insulation and sealing properties. Considering the thickness of the external gasket 54a, if the height of the external flange portion 50b is less than 0.8 mm, the thickness of the external flange portion 50b becomes too thin to ensure sufficient mechanical rigidity. This is particularly serious when the electrode terminal 50 is made of aluminum. Meanwhile, the height of the external flange portion 50b may be appropriately set in consideration of the space margin above the battery. For example, the height of the external flange portion 50b may be set to 2 mm or less, 3 mm or less, 4 mm or less, or 5 mm or less, but the present invention is not limited thereto.

[0135] In yet another embodiment, at least a portion of the external gasket 54a may be exposed outside the external flange portion 50b of the electrode terminal 50. The purpose of exposing the external gasket 54a is to insulate the electrode terminal 50 from the outer surface 52a, which has the opposite polarity to the electrode terminal 50. To electrically insulate the electrode terminal 50 from the outer surface 52a, the exposed width (G) of the external gasket 54a may be 0.1 mm to 1 mm. If the exposed width (G) is less than 0.1 mm, electrical insulation between the electrode terminal 50 and the outer surface 52a may be broken down in a flat surface during high-rate (C-rate) charging and discharging of 300 A or more. If the exposed width (G) is greater than 1 mm, the electrical insulation effect is not further improved, and instead the area of ​​the outer surface 52a used as the negative electrode region is reduced, thereby reducing the contact area of ​​components (e.g., bus bars) used for electrical connection.

[0136] In yet another embodiment, the diameter of the flat portion 50d of the electrode terminal 50 can be determined in consideration of the weld strength between the current collector and the flat portion 50d. The tensile strength of the weld between the flat portion 50d and the current collector can be at least 2 kgf or more, 5 kgf or more, 6 kgf or more, 7 kgf or more, 8 kgf or more, 9 kgf or more, or 10 kgf or more. It is desirable to maximize the tensile strength of the weld by selecting a suitable welding method.

[0137] Referring to Figure 6c, the diameter of the weld pattern Wp formed on the flat portion 50d can be a minimum of 2 mm to satisfy the tensile strength requirement of the weld. The diameter of the weld pattern Wp is calculated by multiplying the area (S) of the weld pattern Wp that appears on the surface of the welded portion by the area (πr 2 ), the equivalent diameter of the corresponding circle (2 × (S / π) 0.5 ) The welding pattern Wp may be continuous or discontinuous. The welding pattern Wp does not have to be circular. When the welding pattern Wp is not circular, the converted diameter (maximum value x 2) can be determined from the maximum value of the distance from the center of the flat portion 50d to the end of the welding pattern Wp.

[0138] The flat portion 50d of the electrode terminal 50 corresponds to the weldable region. The diameter of the weldable region can be 3 mm to 14 mm. If the diameter of the weldable region is smaller than 3 mm, it is difficult to secure a weld pattern with a diameter of 2 mm or more. In particular, when forming a weld pattern using laser welding, it is difficult to secure a weld pattern with a diameter of 2 mm or more due to interference of the laser beam. If the diameter of the weldable region exceeds 14 mm, the diameter of the outer flange portion 50b of the electrode terminal 50 becomes excessively large, making it difficult to secure a sufficient area of ​​the outer surface 52a of the bottom portion 52 of the battery housing used as the negative electrode region.

[0139] When considering the diameter conditions of the welding pattern and the diameter conditions of the weldable area, the ratio of the welding pattern area to the area of ​​the weldable area required to ensure a tensile strength of at least 2 kgf is 2.04% (π1 2 / π7 2 )~44.4%(π1 2 / π1.5 2 ) is desirable.

[0140] In another embodiment, the radius (R1) from the center of the main body portion 50a to the end of the external flange portion 50b may be 10% to 70% of the radius (R2) of the bottom portion 52 of the battery housing 51.

[0141] If R1 is small, there is insufficient welding space when welding a component (bus bar) used for electrical connection of the electrode terminal 50. On the other hand, if R1 is large, there is less welding space when welding a component (bus bar) for electrical connection to the outer surface 52a of the bottom 52 of the battery housing 51 excluding the electrode terminal 50.

[0142] By adjusting the ratio R1 / R2 to be between 10% and 70%, an appropriate welding space can be secured between the electrode terminal 50 and the outer surface 52a of the bottom 52 of the battery housing 51.

[0143] Furthermore, the radius (R3) from the center of the main body 50a of the electrode terminal 50 to the end of the flat portion 50d can be 4% to 30% of the radius (R2) of the bottom 52 of the battery housing 51 as the reference.

[0144] If R3 is small, there may not be enough welding space when welding the current collector to the flat portion 50d of the electrode terminal 50, reducing the welding area of ​​the electrode terminal 50 and increasing contact resistance. In addition, R3 must be smaller than R1, and if R3 is large, the inner flange portion 50c may become thinner, weakening the force with which the inner flange portion 50c crimps the terminal gasket 54, potentially reducing the sealing ability of the terminal gasket 54.

[0145] By adjusting R3 / R2 between 4% and 30%, the welding area between the flat portion 50d of the electrode terminal 50 and the current collector can be sufficiently secured, which not only facilitates the welding process but also reduces the contact resistance in the welding area and prevents a decrease in the sealing ability of the terminal gasket 54.

[0146] According to an embodiment of the present invention, the fixing structure of the electrode terminal 50 can be formed using a crimping jig that moves up and down. First, a preform (not shown) of the electrode terminal 50 is inserted into a through-hole 53 formed in a bottom portion 52 of a battery housing 51, with a terminal gasket 54 interposed therebetween. The preform refers to the electrode terminal before the crimping process is performed.

[0147] Next, a crimping jig is inserted into the inner space of the battery housing 51. The crimping jig has grooves and protrusions corresponding to the final shape of the electrode terminal 50 on the surface facing the preform, in order to press-mold the preform to form the electrode terminal 50.

[0148] Next, the crimping jig is moved downward to press-form the upper portion of the preform, thereby transforming the preform into an electrode terminal 50 that is riveted into the through-hole 53 of the battery housing 51. The pressing depth of the crimping jig can be limited by the flat portion 50d. The flat portion 50d is pre-formed on the main body portion 50a, and the crimping jig has a groove into which the flat portion 50d is inserted. Therefore, when the flat portion 50d contacts the bottom of the groove during the press-forming of the preform, the press-forming is stopped. This allows the inner flange portion 50c and the recess portion 55, which are formed through plastic deformation, to be manufactured uniformly, even during mass production. Furthermore, the flat portion 50d is not deformed or is barely deformed while the preform is pressed by the crimping jig. Therefore, the flat portion 50d can also maintain a uniform shape during mass production. This facilitates the welding process between the flat portion 50d and the current collector, which will be described later, and thereby significantly reduces manufacturing variations.

[0149] While the preform is compressed and deformed by the crimping tool, the outer gasket 54a interposed between the outer flange portion 50b and the outer surface 52a of the bottom 52 of the battery housing 51 is elastically compressed and its thickness is reduced. Furthermore, the portion of the middle gasket 54c interposed between the inner edge 56 of the through-hole 53 and the preform is elastically compressed by the inner flange portion 50c, resulting in a greater thickness reduction than other regions. In particular, the area where the thickness of the middle gasket 54c is reduced intensively is the area indicated by the dotted circle in Figure 6a. This significantly improves the sealing and hermeticity between the riveted electrode terminal 50 and the battery housing 51.

[0150] Preferably, the terminal gasket 54 is sufficiently compressed so that it is not physically damaged when the preform is riveted through a plastic process called caulking, and so that it can ensure a desired sealing strength.

[0151] Preferably, the compression ratio of the terminal gasket 54 may be 30% to 90%. The minimum compression ratio corresponds to the minimum level of compression ratio required to ensure the sealing performance of the electrode terminal 50. The maximum compression ratio corresponds to the maximum level of compression ratio that can be achieved without physically damaging the terminal gasket 54.

[0152] As an example, if terminal gasket 54 is made of polybutylene terephthalate, terminal gasket 54 preferably has a compressibility of 50% or greater at the point where it is compressed to its minimum thickness.

[0153] In the present invention, the compression ratio may be defined as the ratio of the thickness change at the maximum compression point to the pre-compression thickness of the terminal gasket 54. The pre-compression thickness of the inner gasket 54b and the pre-compression thickness of the middle gasket 54c may be uniform, and the maximum compression point may be located near the inner edge 56. Preferably, the compression ratio may be calculated based on the uniform thickness of the inner gasket 54b and the middle gasket 54c.

[0154] As another example, when the terminal gasket 54 is made of polyfluoroethylene, the terminal gasket 54 preferably has a compressibility of 60% or more at the point where it is compressed to its minimum thickness. Preferably, the compressibility can be calculated based on the uniform thickness of the inner gasket 54b and the middle gasket 54c.

[0155] As yet another example, when the terminal gasket 54 is made of polypropylene, the terminal gasket 54 preferably has a compressibility of 60% or more at the point where it is compressed to its minimum thickness. Preferably, the compressibility can be calculated based on the uniform thickness of the inner gasket 54b and the middle gasket 54c.

[0156] Preferably, the crimping jig may be moved up and down at least two times to perform the press-forming of the upper portion of the preform in stages. That is, the preform may be deformed by being press-formed in stages several times. At this time, the pressure applied to the crimping jig may be increased in stages. This distributes the stress applied to the preform over several stages, thereby preventing damage to the terminal gasket 54 during the crimping process. In particular, when the intermediate gasket 54c interposed between the inner edge 56 of the through hole 53 and the preform is compressed in a concentrated manner by the inner flange portion 50c, damage to the gasket is minimized.

[0157] After the press molding of the preform using the crimping jig is completed, the crimping jig is removed from the battery housing 51, and the fixed structure of the electrode terminal 50 according to the embodiment of the present invention is obtained as shown in FIG. 6a.

[0158] According to the above-described embodiment, the crimping jig presses the upper part of the preform by moving up and down inside the battery housing 51. In some cases, a conventional rotary jig may be used to press the preform.

[0159] However, the rotary rotation jig rotates at a predetermined angle relative to the central axis of the battery housing 51. Therefore, a rotary rotation jig with a large rotation radius may interfere with the inner wall of the battery housing 51. Furthermore, if the battery housing 51 is deep, the length of the rotary rotation jig will also be long. In this case, the rotation radius of the end of the rotary rotation jig becomes large, and the preform may not be press-molded sufficiently. Therefore, press molding using a crimping jig is more effective than a method using a rotary rotation jig.

[0160] Meanwhile, the electrode terminal 50 may have various structures depending on the design of the preform and / or the crimping jig and / or the terminal gasket 54 and the amount of pressure applied to the preform during the crimping process.

[0161] FIG. 6b is a partially enlarged cross-sectional view showing the structure of an electrode terminal 50' according to another embodiment of the present invention.

[0162] Referring to FIG. 6b, an electrode terminal 50' according to another embodiment has a structure in which an inner flange portion 50c is riveted toward an inner surface 52b of a bottom portion 52 of a battery housing 51.

[0163] The internal flange portion 50c includes a first section 5c1 extending gradually away from the bottom 52 of the battery housing 51, and a second section 5c2 connected to the first section 5c1 and extending toward the bottom 52 of the battery housing 51.

[0164] The angle (δ) between the surface of the second section 5c2 facing the bottom 52 of the battery housing 51 and the inner surface 52b of the bottom 52 may be 0° to 30°.

[0165] Preferably, the angle (δ) is substantially close to 0 to maximize the sealing performance of the terminal gasket 54. The second section 5c2 strongly presses the inner gasket 54b, thereby increasing the sealing performance of the terminal gasket 54. This effect is enhanced as the angle (δ) approaches 0.

[0166] The height (H3) of the inner flange portion 50c is greater than the height (H2) of the inner gasket 54b. The inner edge of the through-hole 53 has an arc shape with a predetermined curvature. The side wall 55a at the end of the flat portion 50d is inclined toward the flat portion 50d.

[0167] The terminal gasket 54 may include an external gasket 54a interposed between the external flange portion 50b and a first plane P1 on which the outer surface 52a of the bottom 52 of the battery housing 51 is located, an internal gasket 54b interposed between the internal flange portion 50c and a second plane P2 on which the inner surface 52b of the bottom 52 of the battery housing 51 is located, and an intermediate gasket 54c interposed between the main body portion 50a and the through hole 53, connecting the external gasket 54a and the internal gasket 54b.

[0168] Preferably, the thickness of the middle gasket 54c gradually decreases in the direction away from the outer gasket 54a. The inner gasket 54b may decrease to a minimum thickness near the end of the inner flange portion 50c and then slightly increase in thickness toward the top end. This compressible structure of the inner gasket 54b may further improve the sealing performance of the electrode terminal 50'. The compressibility of the inner gasket 54b may be calculated at the minimum thickness point near the end of the inner flange portion 50c.

[0169] Preferably, the fixing structure of the electrode terminals 50, 50' according to the above-described embodiment of the present invention can be applied to a cylindrical battery having a form factor larger than 2170.

[0170] In recent years, as cylindrical batteries are applied to electric vehicles, the form factor of cylindrical batteries has increased compared to conventional 1865, 2170, etc. The increase in form factor brings about an increase in energy density, increased safety against thermal runaway, and improved cooling efficiency.

[0171] In addition, as will be described later, a cylindrical battery employing the electrode terminal 50, 50' fixing structure can perform electrical wiring on only one side. In addition, the electrode terminals 50, 50' have a large cross-sectional area and low resistance, making them highly suitable for fast charging.

[0172] Desirably, the cylindrical battery to which the electrode terminal 50, 50' structure of the present invention is applied may be, for example, a cylindrical battery having a form factor ratio (defined as the diameter of a cylindrical battery divided by its height, i.e., the ratio of height (H) to diameter (Φ)) of greater than about 0.4.

[0173] Here, the form factor refers to a value indicating the diameter and height of a cylindrical battery. Form factors of a cylindrical battery according to an embodiment of the present invention may be, for example, 4611, 4875, 48110, 4880, or 4680. In the form factor number, the first two digits indicate the diameter of the battery, and the remaining digits indicate the height of the battery.

[0174] A battery according to one embodiment of the present invention may be a cylindrical battery having a diameter of about 46 mm, a height of about 110 mm, and a form factor ratio of 0.418.

[0175] Another embodiment of the battery may be a cylindrical battery having a diameter of about 48 mm, a height of about 75 mm, and a form factor ratio of 0.640.

[0176] In yet another embodiment, the battery may be a cylindrical battery having a diameter of about 48 mm, a height of about 110 mm, and a form factor ratio of 0.436.

[0177] In yet another embodiment, the battery may be a cylindrical battery having a diameter of about 48 mm, a height of about 80 mm, and a form factor ratio of 0.600.

[0178] In yet another embodiment, the battery may be a cylindrical battery having a diameter of about 46 mm, a height of about 80 mm, and a form factor ratio of 0.575.

[0179] Conventionally, batteries with a form factor ratio of approximately 0.4 or less have been used. For example, 1865 and 2170 batteries have been used. The 1865 battery has a diameter of approximately 18 mm, a height of approximately 65 mm, and a form factor ratio of 0.277. The 2170 battery has a diameter of approximately 21 mm, a height of approximately 70 mm, and a form factor ratio of 0.300.

[0180] FIG. 7a is a cross-sectional view of a cylindrical battery 70 according to one embodiment of the present invention cut along the longitudinal direction (Y-axis direction).

[0181] Referring to FIG. 7a, a cylindrical battery 70 according to this embodiment includes a jelly-roll-type electrode assembly 71 in which sheet-like first and second electrodes are wound with a separator interposed therebetween, and in which an uncoated portion 72 of the first electrode is exposed at the bottom as a first part of the first electrode, and an uncoated portion 73 of the second electrode is exposed at the top as a second part of the second electrode.

[0182] Here, the first and second portions may not be the uncoated portions but may be other portions of the electrodes. The other portions may be metal tabs electrically connected to the uncoated portions of the electrodes. Furthermore, the electrode assembly 71 may have other shapes besides a jelly roll shape. Of course, the battery may have other shapes, such as a rectangular shape, in addition to a cylindrical shape.

[0183] In an embodiment, the first electrode may be a negative electrode and the second electrode may be a positive electrode, although the reverse is also possible.

[0184] The method for winding the electrode assembly 71 is substantially the same as the method for winding an electrode assembly used in manufacturing a conventional table-less cylindrical battery described above with reference to FIG.

[0185] In the illustration of the electrode assembly 71, only the uncoated portions 72 and 73 that are exposed and extended to the outside of the separator are shown in detail, and the winding structure of the first electrode, the second electrode and the separator is not shown.

[0186] The cylindrical battery 70 also includes a cylindrical battery housing 51 that houses an electrode assembly 71 and is electrically connected to the uncoated portion 72 of the first electrode.

[0187] Preferably, one side (bottom) of the battery housing 51 is open. The bottom 52 of the battery housing 51 has a structure in which the electrode terminals 50 are riveted into the through-holes 53 through a plastic (e.g., caulking) process.

[0188] Specifically, the electrode terminal 50 may include a main body portion 50a inserted into the through hole 53, an external flange portion 50b extending from the outer periphery of a first side of the main body portion 50a exposed from the outer surface 52a of the bottom 52 of the battery housing 51 along the outer surface 52a, an internal flange portion 50c extending from the outer periphery of a second side of the main body portion 50a exposed from the inner surface 52b of the bottom 52 of the battery housing 51 toward the inner surface 52b, and a flat portion 50d provided inside the internal flange portion 50c and surrounded by the internal flange portion 50c.

[0189] The electrode terminal 50 may be replaced by the structure of the electrode terminal 50' shown in FIG. 6b.

[0190] The cylindrical battery 70 may also include a terminal gasket 54 interposed between the electrode terminal 50 and the through-hole 53 .

[0191] The cylindrical battery 70 may also include a sealing body 74 that seals the open end of the battery housing 51 to be insulated from the battery housing 51. Preferably, the sealing body 74 may include a plate-like cap 74a with no polarity and a sealing gasket 74b interposed between the periphery of the cap 74a and the open end of the battery housing 51.

[0192] The cap 74a may be made of a conductive metal material such as aluminum, steel, nickel, etc. The sealing gasket 74b may be made of an insulating and elastic material such as polypropylene, polybutylene terephthalate, polyethylene fluoride, etc. However, the present invention is not limited by the materials of the cap 74a and the sealing gasket 74b.

[0193] The cap 74a may include a venting notch 77 that ruptures when the internal pressure of the battery housing 51 exceeds a critical value. The venting notch 77 may be formed on both sides of the cap 74a. The venting notch 77 may form a continuous or discontinuous circular pattern, a linear pattern, or other patterns on the surface of the cap 74a. The depth and width of the venting notch 77 are determined based on the internal pressure of the battery housing 51 exceeding 15 kgf / cm. 2 ~35kgf / cm 2 The bursting point may be set to burst when the temperature is in the range of 0.5°C.

[0194] The battery housing 51 may include a crimping portion 75 that extends and bends inside the battery housing 51 to secure the sealing body 74, and wraps around and secures the periphery of the cap 74a together with a sealing gasket 74b.

[0195] Preferably, the lower surface of the cap 74a may be located higher than the lower end of the crimping portion 75. This forms a vent space below the cap 74a, allowing gas to be smoothly discharged when the venting notch 77 ruptures.

[0196] The battery housing 51 may also include a beading portion 76 pressed into the interior of the battery housing 51 in an area adjacent to the open end. The beading portion 76 supports the end of the sealing body 74, particularly the outer peripheral surface of the sealing gasket 74b, when the sealing body 74 is secured by the crimping portion 75.

[0197] The cylindrical battery 70 may further include a first current collector 78 welded to the uncoated portion 72 of the first electrode. The first current collector 78 is made of a conductive metal material such as aluminum, steel, or nickel. Preferably, at least a portion 78a of the end of the first current collector 78 that does not contact the uncoated portion 72 of the first electrode may be interposed between the beading portion 76 and the sealing gasket 74b and secured by the crimping portion 75. Optionally, at least a portion 78a of the end of the first current collector 78 may be secured to the inner circumferential surface 76a of the beading portion 76 adjacent to the crimping portion 75 by welding.

[0198] The cylindrical battery 70 may also include a second current collector 79 welded to the uncoated portion 73 of the second electrode. Desirably, at least a portion of the second current collector 79, for example, a central portion 79a, may be welded to the flat portion 50d of the electrode terminal 50.

[0199] Preferably, when welding the second current collector 79, a welding tool can be inserted through a cavity 80 in the core of the electrode assembly 71 to reach the welding point of the second current collector 79. Furthermore, when the second current collector 79 is welded to the flat portion 50d of the electrode terminal 50, the electrode terminal 50 supports the welding area of ​​the second current collector 79, applying strong pressure to the welding area and improving welding quality. Furthermore, the flat portion 50d of the electrode terminal 50 has a large area, ensuring a large welding area. This reduces the contact resistance of the welding area and therefore the internal resistance of the cylindrical battery 70. The face-to-face welding structure between the riveted electrode terminal 50 and the second current collector 79 is very useful for fast charging using a high C-rate current. This is because it reduces the current density per unit area in the cross section in the current flow direction, thereby reducing the amount of heat generated in the current path compared to conventional methods.

[0200] When welding the flat portion 50d of the electrode terminal 50 to the second current collector 79, any one of laser welding, ultrasonic welding, spot welding, and resistance welding may be used.

[0201] For example, when the flat portion 50d and the second current collector 79 are welded by a laser in a continuous or discontinuous arc pattern, the diameter of the arc weld pattern may be 2 mm or more, preferably 4 mm or more. If the diameter of the arc weld pattern satisfies the required conditions, the tensile strength of the weld can be increased to 2 kgf or more to ensure sufficient weld strength.

[0202] As another example, when the flat portion 50d and the second current collector 79 are ultrasonically welded in a circular pattern, the diameter of the circular weld pattern is preferably 2 mm or more. If the diameter of the circular weld pattern satisfies the relevant conditions, the tensile strength of the weld can be increased to 2 kgf or more to ensure sufficient weld strength.

[0203] The diameter of the flat portion 50d, which corresponds to the weldable area, can be adjusted within a range of 3 mm to 14 mm. If the radius of the flat portion 50d is smaller than 3 mm, it is difficult to form a welding pattern with a diameter of 2 mm or more using a laser welding tool, ultrasonic welding tool, etc. Also, if the radius of the flat portion 50d exceeds 14 mm, the electrode terminal 50 becomes excessively large, reducing the area occupied by the outer surface 52a of the bottom 52 of the battery housing 51, making it difficult to connect an electrical connection part (bus bar) through the outer surface 52a.

[0204] Preferably, the diameter of the weld pattern is 2 mm or more to ensure a tensile strength of 2 kgf or more at the welded portion, and the diameter of the weldable area is 3 mm to 14 mm, so the ratio of the weld pattern area to the area of ​​the weldable area is 2.04 (100 × π1 2 / π7 2 )%~44.4(100×π1 2 / π1.5 2 )%.

[0205] The cylindrical battery 70 may further include an insulator 80. The insulator 80 may be interposed between the second current collector 79 and the inner surface 52b of the bottom 52 of the battery housing 51, and between the inner circumferential surface 51a of the side wall of the battery housing 51 and the electrode assembly 71.

[0206] Desirably, the insulator 80 may include a welding hole 80a that exposes the flat portion 50d of the electrode terminal 50 to the second current collector 79. The welding hole 80a may also expose the inner flange portion 50c and the inner gasket 54b together with the flat portion 50d of the electrode terminal.

[0207] Preferably, the insulator 80 covers at least the surface of the second current collector 79 and one side (upper) end of the electrode assembly 71. This prevents the second current collector 79, which has a polarity different from that of the battery housing 51, from coming into contact with the uncoated portion 73 of the second electrode.

[0208] Preferably, the insulator 80 is made of insulating resin and may include an upper plate 80b and a side sleeve 80c. For example, the upper plate 80b and the side sleeve 80c may be an integral injection-molded product. Alternatively, the side sleeve 80c may be replaced with insulating tape. The insulating tape may cover the outer edge of the second current collector 79 as well as the uncoated portion 73 of the second electrode exposed from the outer circumferential surface of the electrode assembly 71.

[0209] Preferably, the insulator 80 and the inner surface 52b of the bottom 52 of the battery housing 51 may be tightly fitted to each other, as shown in Figure 7b. Here, "tightly fitted" means that there is no gap visible to the naked eye. To eliminate the gap, the distance from the inner surface 52b of the bottom 52 of the battery housing 51 to the flat portion 50d of the electrode terminal 50 may be equal to or slightly smaller than the thickness of the insulator 80.

[0210] Preferably, the uncoated portions 72, 73 of the first electrode and / or second electrode may be bent in the radial direction of the electrode assembly 71, for example, from the outer periphery toward the core, to form bent surfaces at the top and bottom of the electrode assembly 71. In addition, the first current collector 78 may be welded to the bent surface formed by bending the uncoated portion 72 of the first electrode, and the second current collector 79 may be welded to the bent surface formed by bending the uncoated portion 73 of the second electrode.

[0211] To alleviate stresses that occur when the uncoated portions 72, 73 are bent, the first electrode and / or the second electrode may have an improved structure that differs from conventional electrodes (see FIG. 1).

[0212] FIG. 8 is a plan view illustrating the structure of an electrode 90 according to a preferred embodiment of the present invention.

[0213] Referring to FIG. 8, electrode 90 includes a sheet-shaped current collector 91 made of a foil of a conductive material, an active material layer 92 formed on at least one surface of current collector 91, and a plain portion 93 on the long edge of current collector 91 where no active material is coated.

[0214] Preferably, the plain portion 93 may include a plurality of notched segments 93a. The plurality of segments 93a may be arranged in a plurality of groups, and the segments 93a in each group may have the same height (length in the Y direction), width (length in the X direction), and / or spacing pitch. The number of segments 93a in each group may be greater or less than that shown in the figure. The segments 93a have a geometric shape formed by combining at least one straight line and / or at least one curved line. Preferably, the segments 93a may be trapezoidal, but may be modified into any shape, including, without limitation, a rectangle, a parallelogram, a semicircle, or a semi-ellipse.

[0215] Preferably, the height of the segment 93a may increase stepwise along a direction parallel to the winding direction of the electrode assembly, for example, from the core side to the outer periphery. Alternatively, the core-side uncoated region 93' adjacent to the core side may not include a segment 93a, and the height of the core-side uncoated region 93' may be lower than the other uncoated regions. Alternatively, the outer periphery uncoated region 93'' adjacent to the outer periphery may not include a segment 93a, and the height of the outer periphery uncoated region 93'' may be lower than the other uncoated regions.

[0216] Optionally, the electrode 90 may include an insulating coating layer 94 covering the boundary between the active material layer 92 and the uncoated portion 93. The insulating coating layer 94 includes an insulating polymer resin and may optionally further include an inorganic filler. The insulating coating layer 94 prevents the end of the active material layer 92 from contacting the active material layer of the opposite polarity facing the separator and serves to structurally support the folding of the divided piece 93a. Therefore, when the electrode 90 is wound into an electrode assembly, it is desirable that at least a portion of the insulating coating layer 94 be exposed to the outside through the separator.

[0217] FIG. 9 is a cross-sectional view taken along the longitudinal direction (Y-axis direction) of an electrode assembly 100 in which the plain partially cut structure of the electrode 90 according to an embodiment of the present invention is applied to the first and second electrodes.

[0218] 9, the electrode assembly 100 can be manufactured using the winding method described with reference to FIG. 2. For ease of explanation, the protruding structures of the uncoated portions 72 and 73 extending outward from the separator are shown in detail, and the winding structures of the first electrode, second electrode, and separator are not shown. The uncoated portion 72 protruding downward is extended from the first electrode, and the uncoated portion 73 protruding upward is extended from the second electrode.

[0219] The varying heights of the uncoated portions 72, 73 are shown only schematically. That is, the heights of the uncoated portions 72, 73 may vary irregularly depending on the cutting position of the cross section. For example, if the side portions of the trapezoidal segment 93a are cut, the height of the uncoated portions in the cross section will be lower than the height of the segment 93a. Therefore, it should be understood that the heights of the uncoated portions 72, 73 shown in the cross-sectional views of the electrode assembly 100 correspond to the average height of the uncoated portions included in each winding turn.

[0220] As shown in FIGS. 10a and 10b, the uncoated portions 72 and 73 may be folded radially from the outer periphery toward the core of the electrode assembly 100. In FIG. 9, the folded portion 101 is indicated by a dotted box. When the uncoated portions 72 and 73 are folded, adjacent segments overlap each other in the radial direction, forming folded surfaces 102 at the top and bottom of the electrode assembly 100. The core-side uncoated portion (93' in FIG. 8) is too low to be folded, and the height (h) of the innermost folded segment is equal to or less than the radial length (r) of the winding region formed by the core-side uncoated portion 93' without a segment structure. Therefore, the cavity 80 in the core of the electrode assembly 100 is not blocked by the folded segments. If the cavity 80 is not blocked, the electrolyte injection process is unaffected and the efficiency of the electrolyte injection is improved. Also, a welding tool can be inserted through the cavity 80 to easily weld the electrode terminal 50 and the second current collector 79 together.

[0221] In the cylindrical battery 70 according to an embodiment of the present invention, the cap 74a of the sealed body 74 does not have polarity. Instead, because the first current collector 78 is connected to the side wall of the battery housing 51, the outer surface 52a of the bottom 52 of the battery housing 51 has the opposite polarity to the electrode terminal 50. Therefore, when connecting multiple batteries in series and / or parallel, wiring such as bus bar connection can be performed at the top of the cylindrical battery 70 using the outer surface 52a of the bottom 52 of the battery housing 51 and the electrode terminal 50. This increases the number of batteries that can be installed in the same space, improving energy density and facilitating electrical wiring work.

[0222] FIG. 11 is a diagram showing a state in which cylindrical batteries 70 according to an embodiment of the present invention are electrically connected using bus bars 150.

[0223] 11, a plurality of cylindrical batteries 70 may be connected in series and parallel at the top using bus bars 150. The number of cylindrical batteries 70 may be increased or decreased depending on the capacity of the battery pack.

[0224] In each cylindrical battery 70, the electrode terminal 50 may have a positive polarity and the outer surface 52a of the bottom 52 of the battery housing 51 may have a negative polarity, or vice versa.

[0225] Preferably, a plurality of cylindrical batteries 70 may be arranged in a plurality of columns and rows. Columns are arranged in the vertical direction in the drawing, and rows are arranged in the horizontal direction in the drawing. To maximize space efficiency, the cylindrical batteries 70 may be arranged in the closest packing structure. The closest packing structure is formed when an equilateral triangle is drawn when the centers of the electrode terminals 50 are connected to each other.

[0226] Preferably, the bus bars 150 may be disposed on top of the plurality of cylindrical batteries 70, more preferably between adjacent columns. Alternatively, the bus bars 150 may be disposed between adjacent rows.

[0227] Preferably, the bus bars 150 connect the batteries arranged in the same row in parallel to each other and connect the batteries arranged in two adjacent rows in series to each other.

[0228] Preferably, bus bar 150 may include a body portion 151, a plurality of first bus bar terminals 152, and a plurality of second bus bar terminals 153 for series and parallel connection.

[0229] The body portion 151 may extend between the electrode terminals 50 of adjacent cylindrical batteries 70, preferably between rows of cylindrical batteries 70. Alternatively, the body portion 151 may extend along the rows of cylindrical batteries 70, but may be regularly folded, such as in a zigzag shape.

[0230] The plurality of first bus bar terminals 152 may protrude from one side of the body portion 151 toward the electrode terminals 50 of each cylindrical battery 70 and be electrically coupled to the electrode terminals 50. The electrical coupling to the electrode terminals 50 may be performed by laser welding, ultrasonic welding, or the like. The plurality of second bus bar terminals 153 may protrude from the other side of the body portion 151 toward the outer surface 52a of the bottom 52 of the battery housing 51 of each cylindrical battery 70 and be electrically coupled to the outer surface 52a. The electrical coupling to the outer surface 52a may be performed by laser welding or ultrasonic welding.

[0231] Preferably, the body portion 151, the plurality of first bus bar terminals 152, and the plurality of second bus bar terminals 153 may be formed from a single conductive metal plate. The metal plate may be an aluminum plate or a copper plate, but the present invention is not limited thereto. Alternatively, the body portion 151, the plurality of first bus bar terminals 152, and the plurality of second bus bar terminals 153 may be manufactured as separate pieces and then joined together by welding or the like.

[0232] In the cylindrical battery 70 according to the present invention, the electrode terminal 50 having a positive polarity and the outer surface 52a of the bottom 52 of the battery housing 51 having a negative polarity are positioned in the same direction, so that electrical connection between the cylindrical batteries 70 can be easily achieved using the bus bar 150.

[0233] In addition, since the electrode terminals 50 and the outer surface 52a of the cylindrical battery 70 have a large area, a sufficient bonding area for the bus bar 150 can be secured, thereby sufficiently reducing the resistance of the battery pack including the cylindrical battery 70.

[0234] FIG. 12a is a partially enlarged view of the electrical connection portion between the bus bar 150 and the cylindrical battery 70, and FIGS. 12b and 12c are views showing the definition of various parameters for designing the upper and lower limits of the diameter of the electrode terminal 50 and the exposed width of the outer surface 52a, taking into account the size of the bus bar terminals 152 and 153.

[0235] 12a, 12b, and 12c, in the cylindrical battery 70, the diameter (E1) of the electrode terminal 50 and the width (E2) of the ring-shaped outer surface 52a can be adaptively adjusted in consideration of the dimensions of the contact areas of the bus bar terminals 152, 153.

[0236] Here, the width (E2) of the outer side surface 52a is the width of the exposed surface parallel to the surface of the electrode terminal 50. Specifically, the width (E2) of the outer side surface 52a is defined as the width of a line segment connecting two points where a straight line (L1) drawn in a radial direction from the center C of the electrode terminal 50 intersects with the inner and outer boundaries of the outer side surface 52a. The width (E2) of the outer side surface 52a is the width of the flat exposed surface excluding the rounded region present on the periphery of the bottom portion 52 and the exposed region 54a' of the outer gasket 54a.

[0237] When viewed from above, the bottom 52 of the battery housing 51 can be divided into an exposed area 54a' of the electrode terminal 50 and the terminal gasket 54, and a rounded area R at the periphery of the outer surface 52a. The rounded area R is a processed area (see FIGS. 7a and 7b) for smoothly connecting the bottom 52 of the battery housing 51 to the side wall of the battery housing 51, and has a width (R d )

[0238] First busbar terminal 152 of busbar 150 branches out to one side opposite the direction of travel of body portion 151 and is electrically connected to electrode terminal 50. At this time, electrode terminal 50 and first busbar terminal 152 form a first overlapping region (shown by hatching) on ​​a plane, and the first overlapping region has a first width (W1). Here, the first overlapping region is a region where electrode terminal 50 and first busbar terminal 152 overlap on a plane.

[0239] The first width (W1) is defined as the maximum value of the distance between any two points selected at the ends of the first overlapping region. The definition of the first width (W1) applies equally to the case where the first overlapping region includes the center of the electrode terminal 50 (FIG. 12b) and the case where the first overlapping region does not include the center of the electrode terminal 50 (FIG. 12c). Referring to FIGS. 12b and 12c, the distance indicated by W1 corresponds to the maximum value of the distance between any two points selected at the ends of the first overlapping region.

[0240] The second busbar terminal 153 of the busbar 150 extends in the opposite direction to the first busbar terminal 152 with respect to the direction of travel of the body portion 151, and is electrically connected to the outer surface 52a of the bottom portion 52 of the battery housing 51. At this time, the second busbar terminal 153 and the outer surface 52a form a second overlapping region (shown by hatching) on ​​a plane, and the second overlapping region has a second width (W2). Here, the second overlapping region is the region where the outer surface 52a and the second busbar terminal 153 overlap on a plane.

[0241] The second width (W2) is defined as the maximum width between two points where each straight line (L2) intersects with the end of the second overlapping region when multiple straight lines (L2) are drawn from the center C of the electrode terminal 50 through the second overlapping region.

[0242] Preferably, the diameter (E1) of the electrode terminal 50 should be at least equal to or larger than the first width (W1) of the first bus bar terminal 152. This is because the first overlapping area between the first bus bar terminal 152 and the electrode terminal 50 should not exceed the electrode terminal 50 on a plane. Also, the diameter (E1) of the electrode terminal 50 can be increased to its maximum until the distance between the boundary of the electrode terminal 50 and the second bus bar terminal 153 corresponds to the width (G) of the exposed area 54a' of the outer gasket 54a. Therefore, the maximum value of the diameter (E1) of the electrode terminal 50 is "D-2×R d -2×G-2×W2".

[0243] Preferably, the width (E2) of the outer surface 52a is a factor that depends on the diameter (E1) of the electrode terminal 50, and must be at least equal to or larger than the second width (W2) of the second bus bar terminal 153. This allows for the formation of an overlapping region between the second bus bar terminal 153 and the outer surface 52a. In addition, the width (E2) of the outer surface 52a is determined by the sum of the outer diameter (D) of the battery housing 51, the diameter (E1) of the electrode terminal 50, the width (2×G) of the exposed region of the outer gasket 54a, and the width (2×R) of the rounded region. d ) is subtracted from the value "D-2 × R d -2×G-E1".

[0244] In conclusion, in the cylindrical battery 70 according to the present invention, it is preferable that the diameter (E1) of the electrode terminal 50 and the width (E2) of the outer surface 52a are designed to satisfy the following relationship: [Formula 1] W1≦E1≦D-2R d -2G-2W2 E2=0.5×(D-2R d -2G-E1) (E1: diameter of the electrode terminal 50, E2: width of the outer surface 52a, D: outer diameter of the battery housing 51, R d : width of round region R measured on a plane, G: width of exposed region 54a' of outer gasket 54a, W1: width of first bus bar terminal 152, W2: width of second bus bar terminal 153)

[0245] In a specific example, when D is 46 mm, W1 and W2 are 6 mm, G is 0.5 mm, and R is 1 mm, the diameter (E1) of the electrode terminal 50 is 6 mm to 31 mm, and the width (E2) of the outer surface 52a is 6 mm to 18.5 mm.

[0246] As another example, when D is 46 mm, W1 and W2 are 6 mm, G is 0.5 mm, and Rd is 1.5 mm, the diameter (E1) of the electrode terminal 50 is 6 mm to 30 mm, and the width (E2) of the outer surface 52a is 6 mm to 18 mm.

[0247] The cylindrical battery 70 of the present invention described above has a structure in which resistance is minimized by expanding the welding area through the bent surfaces, multiple current paths using the first current collector, and minimizing the length of the current paths. The AC resistance of the cylindrical battery 70 measured with a resistance meter between the positive and negative electrodes, i.e., between the electrode terminal 50 and its surrounding flat surface 52a, may be 0.5 mΩ to 4 mΩ, and preferably 1 mΩ to 4 mΩ, which is suitable for fast charging.

[0248] In the present invention, the positive electrode active material coated on the positive electrode and the negative electrode active material coated on the negative electrode may be any active material known in the art without any limitation.

[0249] As an example, the positive electrode active material has the general chemical formula A[A x M y ]O 2+z (A includes at least one element of Li, Na, and K; M includes at least one element selected from Ni, Co, Mn, Ca, Mg, Al, Ti, Si, Fe, Mo, V, Zr, Zn, Cu, Al, Mo, Sc, Zr, Ru, and Cr; x≧0, 1≦x+y≦2, −0.1≦z≦2; and the stoichiometric coefficients x, y, and z are selected to maintain electroneutrality of the compound).

[0250] As another example, the positive electrode active material may be an alkali metal compound xLiM disclosed in U.S. Pat. No. 6,677,082, U.S. Pat. No. 6,680,143, etc. 1 O2.(1-x)Li2M 2 O3(M 1 contains at least one element having an average oxidation state of 3; M 2 contains at least one element having an average oxidation state of 4; 0≦x≦1).

[0251] In yet another example, the positive electrode active material may be a compound represented by the general chemical formula Li a M 1 x Fe 1-x M 2 y P 1-y M3 z O 4-z (M 1 contains at least one element selected from Ti, Si, Mn, Co, Fe, V, Cr, Mo, Ni, Nd, Al, Mg and Al; M 2 contains at least one element selected from Ti, Si, Mn, Co, Fe, V, Cr, Mo, Ni, Nd, Al, Mg, Al, As, Sb, Si, Ge, V and S; M 3 contains a halogen group element selectively containing F; 0 < a ≤ 2, 0 ≤ x ≤ 1, 0 ≤ y < 1, 0 ≤ z < 1; the stoichiometric coefficients a, x, y and z are selected so that the compound maintains electrical neutrality), or it may be a lithium metal phosphate represented by Li3M2(PO4)3 [M contains at least one element selected from Ti, Si, Mn, Fe, Co, V, Cr, Mo, Ni, Al, Mg and Al].

[0252] Desirably, the positive electrode active material may contain primary particles and / or secondary particles formed by aggregating the primary particles.

[0253] As an example, as the negative electrode active material, a carbon material, a lithium metal or a lithium metal compound, silicon or a silicon compound, tin or a tin compound, etc. can be used. Metal oxides such as TiO2 and SnO2 with a potential of less than 2V can also be used as the negative electrode active material. As the carbon material, both low-crystalline carbon and high-crystalline carbon can be used.

[0254] As the separation membrane, a porous polymer film, for example, a porous polymer film made of a polyolefin-based polymer such as a polyethylene homopolymer, a polypropylene homopolymer, an ethylene / butene copolymer, an ethylene / hexene copolymer, an ethylene / methacrylate copolymer, etc., can be used alone or by laminating these. As another example, the separation membrane can use a normal porous non-woven fabric, for example, a non-woven fabric made of high-melting-point glass fibers, polyethylene terephthalate fibers, etc.

[0255] At least one surface of the separator may include a coating layer of inorganic particles. Alternatively, the separator itself may be made of a coating layer of inorganic particles. The particles constituting the coating layer may have a structure in which they are bound with a binder so that there is interstitial volume between adjacent particles.

[0256] The inorganic particles may be made of an inorganic material having a dielectric constant of 5 or more. Non-limiting examples of the inorganic particles include Pb(Zr,Ti)O3 (PZT), Pb 1-x La x Zr 1-y Ti y O3(PLZT), PB(Mg3Nb 2 / 3 )O3-PbTiO3 (PMN-PT), BaTiO3, hafnia (HfO2), SrTiO3, TiO2, Al2O3, ZrO2, SnO2, CeO2, MgO, CaO, ZnO, and Y2O3.

[0257] The electrolyte is A + B - where A + Li + , Na + , K. + or a combination thereof. - is F - , Cl - , Br - , I - , NO3 - , N(CN)2 - , BF4 - , ClO4 - , AlO4 - , AlCl4 - , PF6 - , SbF6 - , AsF6 - , BF2C2O4 - , BC4O8 - , (CF3)2PF4 - , (CF3)3PF3 - , (CF3)4PF2 -, (CF3)5PF - , (CF3)6P - , CF3SO3 - , C4F9SO3 - , CF3CF2SO3 - , (CF3SO2)2N - , (FSO2)2N - , CF3CF2(CF3)2CO - , (CF3SO2)2CH - , (SF5)3C - , (CF3SO2)3C - , CF3(CF2)7SO3 - , CF3CO2 - , CH3CO2 - , SCN - and (CF3CF2SO2)2N - The anion comprises one or more anions selected from the group consisting of:

[0258] The electrolyte may be dissolved in an organic solvent such as propylene carbonate (PC), ethylene carbonate (EC), diethyl carbonate (DEC), dimethyl carbonate (DMC), dipropyl carbonate (DPC), dimethyl sulfoxide, acetonitrile, dimethoxyethane, diethoxyethane, tetrahydrofuran, N-methyl-2-pyrrolidone (NMP), ethyl methyl carbonate (EMC), γ-butyrolactone, or a mixture thereof.

[0259] The cylindrical battery 70 according to the above-described embodiment can be used to manufacture a battery pack.

[0260] FIG. 13 is a diagram schematically illustrating the configuration of a battery pack according to an embodiment of the present invention.

[0261] 13, a battery pack 200 according to an embodiment of the present invention includes an assembly of electrically connected cylindrical batteries 201 and a pack housing 202 that accommodates the assembly. The cylindrical batteries 201 are the batteries according to the above-described embodiments. For convenience of illustration, components such as bus bars for electrical connection of the cylindrical batteries 201, a cooling unit, and external terminals are not shown.

[0262] The battery pack 200 is mounted on a vehicle. The vehicle may be, for example, an electric vehicle, a hybrid vehicle, or a plug-in hybrid vehicle. The vehicle may be a four-wheeled vehicle or a two-wheeled vehicle.

[0263] FIG. 14 is a diagram illustrating a vehicle including the battery pack 200 of FIG.

[0264] 14, an automobile V according to an embodiment of the present invention includes a battery pack 200 according to an embodiment of the present invention. The automobile V operates by receiving a supply of power from the battery pack 200 according to an embodiment of the present invention.

[0265] According to one aspect of the present invention, the electrode terminal structure of a battery is improved to increase space efficiency within a battery housing, thereby reducing the internal resistance of the battery and increasing the energy density.

[0266] According to another aspect of the present invention, the problem of internal heat generation occurring during rapid charging can be alleviated by improving the electrode terminal structure of the battery to increase the cross-sectional area of ​​the current path.

[0267] According to yet another aspect of the present invention, electrical wiring for connecting batteries in series and / or in parallel can be performed on only one side of the battery.

[0268] According to yet another aspect of the present invention, a battery pack manufactured using a battery having an improved structure and a vehicle including the same can be provided.

[0269] As described above, the present invention has been described using limited embodiments and drawings, but the present invention is not limited thereto, and it goes without saying that various modifications and variations can be made by a person having ordinary knowledge in the technical field to which the present invention pertains within the technical spirit of the present invention and the equivalent scope of the claims.

[0270] [Section 1] a battery housing having a bottom portion with one side open and the other side having a through hole; an electrode terminal attached to the through hole so as not to come into contact with an inner wall of the through hole; a terminal gasket interposed between the electrode terminal and the through hole, The electrode terminal is a main body portion inserted into the through hole; an external flange portion extending from the first side of the main body portion along an outer surface of the bottom of the battery housing; an inner flange portion extending from the second side of the main body portion toward an inner surface of the bottom portion of the battery housing and crimping the terminal gasket; a flat portion provided inside the inner flange portion. [Section 2] Item 2. The electrode terminal fixing structure according to item 1, wherein the flat portion and the inner surface of the bottom of the battery housing are parallel to each other. [Section 3] Item 3. The electrode terminal fixing structure according to item 1 or 2, wherein the electrode terminal is made of metal, and the internal flange portion is formed by plastic processing the first side of the main body portion. [Section 4] Item 4. The electrode terminal fixing structure according to any one of items 1 to 3, wherein the electrode terminal is a rivet terminal riveted through the through hole by the internal flange portion. [Section 5] Item 5. The electrode terminal fixing structure according to any one of items 1 to 4, wherein an angle between a surface of the inner flange portion facing the bottom of the battery housing and an inner surface of the bottom of the battery housing is 0° to 60°. [Section 6] 5. The electrode terminal fixing structure according to any one of items 1 to 4, wherein the internal flange portion includes a first section that gradually becomes farther away from the bottom of the battery housing and a second section that is connected to the first section and extends toward the bottom of the battery housing, and an angle between a surface of the second section facing the bottom and an inner surface of the bottom is 0° to 30°. [Section 7] Item 7. The electrode terminal fixing structure according to any one of items 1 to 6, wherein a recess is provided between the inner flange portion and the flat portion. [Section 8] Item 8. The electrode terminal fixing structure according to item 7, wherein the recessed portion is a closed-loop groove recessed in the central axis direction of the main body portion. [Section 9] Item 9. The electrode terminal fixing structure according to item 7 or 8, wherein the recessed portion has an asymmetric cross section. [Section 10] Item 10. The electrode terminal fixing structure according to item 9, wherein the asymmetric cross section includes a side wall of the flat portion and an inclined surface of the inner flange portion connected to an end of the side wall of the flat portion. [Section 11] Item 11. The electrode terminal fixing structure according to item 10, wherein the side wall is perpendicular to the inner surface of the bottom of the battery housing. [Section 12] Item 11. The electrode terminal fixing structure according to item 10, wherein the side wall is inclined toward the flat portion. [Section 13] Item 13. The electrode terminal fixing structure according to any one of items 1 to 12, wherein the thickness of the inner flange portion gradually decreases as it becomes farther from the main body portion. [Section 14] The terminal gasket is an outer gasket interposed between the outer flange portion and a first plane on which an outer surface of the bottom portion of the battery housing is located; an internal gasket interposed between the internal flange portion and a second plane on which the inner surface of the bottom portion of the battery housing is located; Item 14. The electrode terminal fixing structure according to any one of items 1 to 13, further comprising: an intermediate gasket interposed between the main body and the through hole and connecting the outer gasket and the inner gasket. [Section 15] Item 15. The electrode terminal fixing structure according to item 14, wherein the thickness of the intermediate gasket varies depending on the position. [Section 16] Item 16. The electrode terminal fixing structure according to item 15, wherein the terminal gasket has a minimum thickness at the intermediate gasket. [Section 17] Item 16. The electrode terminal fixing structure according to item 15, wherein the thickness of the region of the intermediate gasket adjacent to the first plane increases as it approaches the first plane. [Section 18] Item 16. The electrode terminal fixing structure according to item 15, wherein the thickness of the region of the intermediate gasket adjacent to the second plane increases as it approaches the second plane. [Section 19] Item 16. The electrode terminal fixing structure according to item 15, wherein the thickness of the central region of the intermediate gasket located between the first plane and the second plane is uniform. [Section 20] Item 15. The electrode terminal fixing structure according to item 14, wherein the thickness of a region of the intermediate gasket interposed between the inner edge of the through hole connected to the inner surface of the bottom and the inner flange portion is relatively smaller than that of other regions of the intermediate gasket. [Section 21] Item 15. The electrode terminal fixing structure according to item 14, wherein the thickness of the intermediate gasket gradually decreases in a direction away from the outer flange portion. [Section 22] Item 16. The electrode terminal fixing structure according to item 15, wherein the thickness of the region of the internal gasket between the inner surface of the bottom and the vicinity of the end of the internal flange is the thinnest. [Section 23] Item 15. The electrode terminal fixing structure according to item 14, wherein an inner edge of the through hole includes an opposing surface that faces the inner flange portion. [Section 24] Item 15. The electrode terminal fixing structure according to item 14, wherein the internal gasket extends longer than the internal flange portion and has an exposed end. [Section 25] Item 15. The electrode terminal fixing structure according to item 14, wherein the height of the flat portion is equal to or greater than the height of the end of the internal gasket, based on the inner surface of the bottom of the battery housing. [Section 26] Item 26. The electrode terminal fixing structure according to any one of items 1 to 25, wherein the height of the flat portion is equal to or greater than the height of the inner flange portion based on the inner surface of the bottom of the battery housing. [Section 27] Item 15. The electrode terminal fixing structure according to item 14, wherein the height of the internal flange portion is greater than the height of the end of the internal gasket, based on the inner surface of the bottom of the battery housing. [Section 28] Item 28. The electrode terminal fixing structure according to any one of items 1 to 27, wherein the height of the inner flange portion is 0.5 mm to 3.0 mm based on the inner surface of the bottom of the battery housing. [Section 29] Item 29. The electrode terminal fixing structure according to item 28, wherein the height of the electrode terminal from the lower surface of the outer flange portion to the surface of the flat portion is 4 mm to 7 mm. [Section 30] Item 30. The electrode terminal fixing structure according to any one of items 1 to 29, wherein the height of the external flange portion is 0.8 mm or more based on the outer surface of the bottom of the battery housing. [Section 31] a portion of the outer gasket exposed to the outside of the outer flange portion; Item 15. The electrode terminal fixing structure according to item 14, wherein the width of the exposed portion of the outer gasket measured in a direction parallel to the outer surface of the bottom of the battery housing is 0.1 mm to 1 mm. [Section 32] Item 15. The electrode terminal fixing structure according to item 14, wherein the radius from the center of the main body to the end of the external flange is 10% to 70% of the radius of the bottom of the battery housing. [Section 33] Item 33. The electrode terminal fixing structure according to any one of items 1 to 32, wherein the radius from the center of the main body to the end of the flat portion is 4% to 30% of the radius of the bottom of the battery housing. [Section 34] When the ratio of the thickness change amount at the maximum compression point to the thickness before compression of the terminal gasket is defined as a compression ratio, Item 15. The electrode terminal fixing structure according to item 14, wherein the terminal gasket has a compressibility of 30% to 90%. [Section 35] the terminal gasket comprises polybutylene terephthalate, polyfluoroethylene, or polypropylene; Item 35. The electrode terminal fixing structure according to item 34, wherein the terminal gasket has a compressibility of 50% to 90%. [Section 36] Item 34 or 35, wherein the thickness of the intermediate gasket of the terminal gasket before compression and the thickness of the inner gasket before compression are substantially the same, and the compression rates of the intermediate gasket and the inner gasket are 50% to 90%. [Section 37] an electrode assembly in which a first electrode and a second electrode are wound with a separator interposed therebetween, the electrode assembly including a first portion of the first electrode and a second portion of the second electrode extending from both ends and exposed to the outside of the separator; a battery housing that houses the electrode assembly and is electrically connected to the first electrode; an electrode terminal that is attached through the through hole formed in the bottom of the battery housing so as not to come into contact with an inner wall of the through hole and is electrically connected to the second electrode, a main body portion inserted into the through hole; an external flange portion extending from the first side of the main body portion along an outer surface of the bottom of the battery housing; an inner flange portion extending from the second side of the main body portion toward an inner surface of the bottom portion of the battery housing; an electrode terminal including a flat portion provided inside the inner flange portion; a terminal gasket interposed between the electrode terminal and the through hole; a seal sealing the open end of the battery housing so as to be insulative from the battery housing. [Section 38] the battery housing includes a beading portion pressed into the interior of the battery housing in an area adjacent the open end; Item 38. The battery according to item 37, wherein the sealing body includes a non-polarized cap and a sealing gasket interposed between the periphery of the cap and the open end of the battery housing. [Section 39] Item 39. The battery according to item 38, wherein the battery housing further includes a crimping portion that extends and folds inside the battery housing and wraps around and fixes the periphery of the cap together with the sealing gasket. [Section 40] 40. The battery of claim 38 or 39, wherein the cap includes a venting notch that ruptures when the internal pressure of the battery housing exceeds a critical value. [Section 41] The venting notch is formed so that the internal pressure of the battery housing is 15 kgf / cm 2 ~35kgf / cm 2 41. The battery according to paragraph 40, which explodes when [Section 42] a first current collector coupled to the first portion of the first electrode; Item 40. The battery according to item 39, wherein at least a portion of the end of the first current collector that does not contact the first portion of the first electrode is interposed between the beading portion and the sealing gasket and fixed by the crimping portion. [Section 43] Item 43. The battery according to item 42, wherein at least a portion of the end of the first current collector is fixed to the inner circumferential surface of the beading portion adjacent to the crimping portion by welding. [Section 44] a second current collector coupled to the second portion of the second electrode; Item 44. The battery according to any one of items 37 to 43, wherein at least a portion of the second current collector is coupled to a flat portion of the electrode terminal. [Section 45] the second current collector and the flat portion of the electrode terminal are joined by welding, Item 45. The battery according to item 44, wherein the tensile strength of the weld between the second current collector and the flat portion of the electrode terminal is 2 kgf or more. [Section 46] Item 46. The battery according to item 45, wherein the equivalent diameter of the welding pattern exposed on the surface of the second current collector is 2 mm or more. [Section 47] Item 47. The battery according to item 46, wherein the diameter of the flat portion of the electrode terminal is 3 mm to 14 mm. [Section 48] Item 48. The battery according to any one of items 45 to 47, wherein the ratio of the area of ​​the welding pattern exposed on the surface of the second current collector to the area of ​​the flat portion of the electrode terminal is 2.04% to 44.4%. [Section 49] Item 49. The battery according to any one of items 44 to 48, further comprising an insulator interposed between the second current collector and the inner surface of the bottom of the battery housing, and between the inner circumferential surface of the side wall of the battery housing and the electrode assembly. [Section 50] Item 50. The battery according to item 49, wherein the insulator includes a welding hole that exposes the flat portion of the electrode terminal to the second current collector side, and covers the surface of the second current collector and one side end of the electrode assembly. [Section 51] Item 51. The battery according to item 50, wherein the height from the inner surface of the bottom of the battery housing to the flat portion of the electrode terminal is equal to or smaller than the thickness of the insulator. [Section 52] The terminal gasket is an outer gasket interposed between the outer flange portion and a first plane on which an outer surface of the bottom portion of the battery housing is located; an internal gasket interposed between the internal flange portion and a second plane on which the inner surface of the bottom portion of the battery housing is located; Item 52. The battery according to item 50 or 51, further comprising an intermediate gasket interposed between the main body and the through hole, connecting the external gasket and the internal gasket. [Section 53] Item 53. The battery according to item 52, wherein an end of the internal gasket is exposed outside the internal flange portion. [Section 54] Item 53. The battery according to item 52, wherein the welding hole exposes the flat portion and the inner flange portion of the electrode terminal. [Section 55] Item 54. The battery according to item 53, wherein the welding hole exposes the flat portion and the internal flange portion of the electrode terminal and the internal gasket. [Section 56] Item 37 to 55, wherein a first bus bar terminal is electrically coupled to the surface of the electrode terminal, and a second bus bar terminal is electrically coupled to the outer surface of the bottom of the battery housing. The battery according to any one of items 37 to 55. [Section 57] the first bus bar terminals overlap the electrode terminals in a plane to form a first overlapping region, and the second bus bar terminals overlap the outer surface of the bottom of the battery housing in a plane to form a second overlapping region; The diameter of the electrode terminal and the width of the outer surface of the bottom of the battery housing satisfy the following formula 1: [Formula 1] W1≦E1≦D-2R d -2G-2W2 E2=0.5×(D-2R d -2G-E1) E1 is the diameter of the outer flange portion of the electrode terminal, E2 is the width of the exposed surface of the outer surface of the bottom of the battery housing that is parallel to the surface of the electrode terminal, D is the outer diameter of the battery housing, and R d Item 57. The battery according to item 56, wherein W is the width of the rounded area of ​​the periphery of the battery housing measured on a plane, G is the exposed width of the outer gasket through the periphery of the electrode terminal, W1 is the maximum distance between any two points selected at the end of the first overlapping area, and W2 is the maximum distance between two points where multiple straight lines passing through the center of the electrode terminal intersect with the end of the second overlapping area. [Section 58] 58. The battery of any one of paragraphs 37 to 57, wherein the form factor ratio of the battery's diameter divided by its height is greater than 0.4. [Section 59] A battery pack comprising the battery of any one of paragraphs 37 to 58. [Section 60] The plurality of batteries are arranged in a predetermined number of rows; Item 60. A battery pack according to item 59, wherein the electrode terminals of each of the plurality of batteries and the outer surface of the bottom of the battery housing are arranged facing upward. [Section 61] A plurality of bus bars are included which connect the plurality of batteries in series and in parallel, the plurality of bus bars are disposed on top of the plurality of batteries; Each of the plurality of bus bars is a body portion extending between the electrode terminals of adjacent batteries; a plurality of first bus bar terminals extending to one side of the body portion and electrically coupled to the electrode terminals of the battery located on the one side; Item 61. The battery pack of item 60, further comprising: a plurality of second bus bar terminals extending to the other side of the body portion and electrically coupled to the outer surface of the bottom of the battery housing of the battery located on the other side. [Section 62] Item 62. The battery pack according to any one of items 59 to 61, wherein the AC resistance measured between the electrode terminal of the battery and the outer surface of the bottom of the battery housing is 4 mΩ or less. [Section 63] Item 63. A vehicle comprising at least one battery pack according to any one of items 59 to 62. [Section 64] a body portion including an upper surface, a lower surface, and an outer surface; an external flange portion extending from the outer surface of the main body portion along the outer surface of the bottom of the battery housing; an inner flange portion extending from an outer surface of the body portion toward an inner surface of the bottom portion of the battery housing; The electrode terminal has an upper surface of the main body connected to a current collector. [Section 65] Item 65. The electrode terminal according to item 64, wherein the upper surface of the main body is located above the inner flange. [Section 66] Item 66. The electrode terminal according to item 64 or 65, wherein the upper surface of the main body is flat. [Section 67] Item 67. The electrode terminal according to any one of items 64 to 66, wherein a groove is provided between the main body portion and the internal flange portion. [Section 68] Item 68. The electrode terminal according to item 67, wherein the groove includes a first surface formed by the outer surface of the main body portion and a second surface formed by the upper surface of the internal flange portion. [Section 69] Item 69. The electrode terminal according to item 68, wherein the first surface and the second surface are asymmetric. [Section 70] Item 69. The electrode terminal according to any one of items 64 to 69, wherein the angle between the inner flange portion and the outer flange portion is 0° to 60°.

Claims

1. a battery housing having a bottom portion with one side open and the other side having a through hole; an electrode terminal attached to the through hole so as not to come into contact with an inner wall of the through hole; a terminal gasket interposed between the electrode terminal and the through hole, The electrode terminal is a main body portion inserted into the through hole; an external flange portion extending from the first side of the body portion along an outer surface of the bottom of the battery housing; an inner flange portion extending from the second side of the main body portion toward an inner surface of the bottom portion of the battery housing and crimping the terminal gasket; a weldable region provided inside the inner flange portion and welded to the current collector, When the bottom portion is viewed from the side, the exposed surface of the external flange portion facing the first side surface and the outer surface of the bottom portion forms an electrical contact surface that extends continuously from the center of the first side surface to the periphery of the exposed surface of the external flange portion.

2. The electrode terminal fixing structure according to claim 1 , wherein the weldable area is a flat portion parallel to an inner surface of the bottom of the battery housing.

3. 3. The electrode terminal fixing structure according to claim 1, wherein the electrode terminal is made of metal, and the inner flange portion is formed by plastic working the first side of the main body portion.

4. The electrode terminal fixing structure according to claim 1 , wherein the electrode terminal is a rivet terminal riveted through the through hole by the inner flange portion.

5. 5. The electrode terminal fixing structure according to claim 1, wherein an angle between a surface of the inner flange portion facing the bottom of the battery housing and an inner surface of the bottom of the battery housing is 0° to 60°.

6. 5. The electrode terminal fixing structure according to claim 1, wherein the inner flange portion includes a first section that gradually becomes farther away from the bottom of the battery housing and a second section that is connected to the first section and extends toward the bottom of the battery housing, and an angle between a surface of the second section facing the bottom and an inner surface of the bottom is 0° to 30°.

7. The electrode terminal fixing structure according to claim 2 , wherein a recess is provided between the inner flange portion and the flat portion.

8. The electrode terminal fixing structure according to claim 7 , wherein the recessed portion is a closed-loop groove recessed in the central axis direction of the main body portion.

9. The electrode terminal fixing structure according to claim 7 or 8, wherein the recessed portion has an asymmetric cross section.

10. The electrode terminal fixing structure according to claim 9 , wherein the asymmetric cross section includes a side wall of the flat portion and an inclined surface of the inner flange portion connected to an end of the side wall of the flat portion.

11. The electrode terminal fixing structure according to claim 10 , wherein the side wall is perpendicular to an inner surface of the bottom of the battery housing.

12. The electrode terminal fixing structure according to claim 10 , wherein the side wall is inclined toward the flat portion.

13. The electrode terminal fixing structure according to claim 1 , wherein the thickness of the inner flange portion gradually decreases with increasing distance from the main body portion.

14. The terminal gasket is an outer gasket interposed between the outer flange portion and a first plane on which an outer surface of the bottom portion of the battery housing is located; an internal gasket interposed between the internal flange portion and a second plane on which the inner surface of the bottom portion of the battery housing is located; The electrode terminal fixing structure according to claim 1 , further comprising: an intermediate gasket interposed between the main body portion and the through hole, the intermediate gasket connecting the outer gasket and the inner gasket.

15. The electrode terminal fixing structure according to claim 14 , wherein the thickness of the intermediate gasket varies depending on the position.

16. The electrode terminal fixing structure according to claim 15 , wherein the terminal gasket has a minimum thickness at the intermediate gasket.

17. The electrode terminal fixing structure according to claim 15 , wherein a thickness of the region of the intermediate gasket adjacent to the first plane increases toward the first plane.

18. The electrode terminal fixing structure according to claim 15 , wherein a thickness of the region of the intermediate gasket adjacent to the second plane increases toward the second plane.

19. The electrode terminal fixing structure according to claim 15, wherein the thickness of the central region of the intermediate gasket located between the first plane and the second plane is uniform.

20. 15. The electrode terminal fixing structure according to claim 14, wherein a thickness of a region of the intermediate gasket interposed between an inner edge of the through hole connected to the inner surface of the bottom and the inner flange portion is relatively smaller than that of other regions of the intermediate gasket.

21. 15. The electrode terminal fixing structure according to claim 14, wherein the thickness of the intermediate gasket gradually decreases in a direction away from the outer flange portion.

22. 16. The electrode terminal fixing structure according to claim 15, wherein the thickness of the inner gasket is thinnest in a region between the inner surface of the bottom portion and a vicinity of an end of the inner flange portion.

23. The electrode terminal fixing structure according to claim 14 , wherein an inner edge of the through hole includes an opposing surface facing the inner flange portion.

24. The electrode terminal fixing structure according to claim 14 , wherein upper and lower ends of the inner wall of the through hole are chamfered to form tapered surfaces toward the electrode terminal.

25. The electrode terminal fixing structure according to claim 14 , wherein the inner gasket extends longer than the inner flange portion, and an end portion of the inner gasket is exposed.

26. The electrode terminal fixing structure according to claim 14 , wherein the height of the flat portion is equal to or greater than the height of the end of the inner gasket relative to the inner surface of the bottom of the battery housing.

27. 3. The electrode terminal fixing structure according to claim 2, wherein the height of the flat portion is equal to or greater than the height of the inner flange portion with respect to the inner surface of the bottom of the battery housing.

28. 15. The electrode terminal fixing structure according to claim 14, wherein the height of the inner flange portion is greater than the height of the end of the inner gasket with respect to the inner surface of the bottom of the battery housing.

29. 29. The electrode terminal fixing structure according to claim 1, wherein the height of the inner flange portion is 0.5 mm to 3.0 mm relative to the inner surface of the bottom of the battery housing.

30. The electrode terminal fixing structure according to claim 29, which relies on claim 2, wherein the height of the electrode terminal from the lower surface of the external flange portion to the surface of the flat portion is 4 mm to 7 mm.

31. 31. The electrode terminal fixing structure according to claim 1, wherein the height of the external flange portion relative to the outer surface of the bottom of the battery housing is 0.8 mm or more.

32. a portion of the outer gasket exposed to the outside of the outer flange portion; 15. The electrode terminal fixing structure according to claim 14, wherein the width of the exposed portion of the outer gasket measured in a direction parallel to the outer surface of the bottom of the battery housing is 0.1 mm to 1 mm.

33. 15. The electrode terminal fixing structure according to claim 14, wherein a radius from the center of the main body to an end of the external flange is 10% to 70% of a radius of the bottom of the battery housing.

34. 3. The electrode terminal fixing structure according to claim 2, wherein a radius from the center of the main body to the end of the flat portion is 4% to 30% of the radius of the bottom of the battery housing.

35. When the ratio of the thickness change amount at the maximum compression point to the thickness before compression of the terminal gasket is defined as a compression ratio, 15. The electrode terminal fixing structure according to claim 14, wherein the terminal gasket has a compressibility of 30% to 90%.

36. the terminal gasket comprises polybutylene terephthalate, polyfluoroethylene, or polypropylene; 36. The electrode terminal fixing structure according to claim 35, wherein the compressibility of the terminal gasket is 50% to 90%.

37. 37. The electrode terminal fixing structure according to claim 35 or 36, wherein the thickness of the intermediate gasket of the terminal gasket before compression and the thickness of the inner gasket before compression are substantially the same, and the compression rates of the intermediate gasket and the inner gasket are 50% to 90%.

38. an electrode assembly in which a first electrode and a second electrode are wound with a separator interposed therebetween, the electrode assembly including a first portion of the first electrode and a second portion of the second electrode extending from both ends and exposed to the outside of the separator; a battery housing that houses the electrode assembly and is electrically connected to the first electrode; an electrode terminal that is attached to the battery housing so as to pass through the through hole formed in the bottom portion of the battery housing without contacting an inner wall of the through hole and is electrically connected to the second electrode, a main body portion inserted into the through hole; an external flange portion extending from the first side of the body portion along an outer surface of the bottom of the battery housing; an inner flange portion extending from the second side of the main body portion toward an inner surface of the bottom portion of the battery housing; a flat portion provided on the inside of the inner flange portion, an electrode terminal, wherein when the bottom portion is viewed from the first side, an exposed surface of the external flange portion facing the first side surface and the outer surface of the bottom portion forms an electrical contact surface that continuously extends from the center of the first side surface to the periphery of the exposed surface of the external flange portion; a terminal gasket interposed between the electrode terminal and the through hole; a seal sealing the open end of the battery housing so as to be insulative from the battery housing.

39. the battery housing includes a beading portion pressed into the interior of the battery housing in an area adjacent the open end; 39. The battery of claim 38, wherein the sealing body includes a non-polarized cap and a sealing gasket interposed between a periphery of the cap and an open end of the cell housing.

40. 40. The battery of claim 39, wherein the battery housing further includes a crimping portion that extends and folds inside the battery housing to wrap around and secure the periphery of the cap together with the sealing gasket.

41. 41. The battery of claim 39 or 40, wherein the cap includes a venting notch that ruptures when the internal pressure of the battery housing exceeds a critical value.

42. The venting notch is formed so that the internal pressure of the battery housing is 15 kgf / cm ２ ~35 kgf / cm ２ 42. The battery of claim 41, which explodes when

43. 41. The battery of claim 40, wherein the lower surface of the cap is located above the lower end of the crimping portion.

44. a first current collector coupled to the first portion of the first electrode; 41. The battery of claim 40, wherein at least a portion of an end of the first current collector that does not contact the first portion of the first electrode is interposed between the beading portion and the sealing gasket and fixed by the crimping portion.

45. 45. The battery of claim 44, wherein at least a portion of the end of the first current collector is fixed to an inner circumferential surface of the beading portion adjacent to the crimping portion through welding.

46. a second current collector coupled to the second portion of the second electrode; 46. ​​The battery of any one of claims 38 to 45, wherein at least a portion of the second current collector is coupled to a flat portion of the electrode terminal.

47. the second current collector and the flat portion of the electrode terminal are joined by welding, 47. The battery according to claim 46, wherein a tensile strength of a weld between the second current collector and the flat portion of the electrode terminal is 2 kgf or more.

48. 48. The battery of claim 47, wherein the equivalent diameter of the weld pattern exposed on the surface of the second current collector is 2 mm or more.

49. The battery of claim 48, wherein the diameter of the flat portion of the electrode terminal is 3 mm to 14 mm.

50. 50. The battery according to claim 47, wherein a ratio of an area of ​​the welding pattern exposed on the surface of the second current collector to an area of ​​the flat portion of the electrode terminal is 2.04% to 44.4%.

51. 51. The battery of any one of claims 46 to 50, further comprising an insulator interposed between the second current collector and the inner surface of the bottom of the battery housing, and between the inner peripheral surface of the side wall of the battery housing and the electrode assembly.

52. 52. The battery of claim 51, wherein the insulator includes a welding hole that exposes a flat portion of the electrode terminal toward the second current collector, and covers a surface of the second current collector and one side end of the electrode assembly.

53. 53. The battery of claim 52, wherein the height from the inner surface of the bottom of the battery housing to the flat portion of the electrode terminal is equal to or smaller than the thickness of the insulator.

54. The terminal gasket is an outer gasket interposed between the outer flange portion and a first plane on which an outer surface of the bottom portion of the battery housing is located; an internal gasket interposed between the internal flange portion and a second plane on which the inner surface of the bottom portion of the battery housing is located; 54. The battery of claim 52 or 53, further comprising: an intermediate gasket interposed between the main body and the through-hole, connecting the outer gasket and the inner gasket.

55. 55. The battery of claim 54, wherein an end of the internal gasket is exposed outside the internal flange portion.

56. 55. The battery of claim 54, wherein the weld hole exposes a flat portion and the inner flange portion of the electrode terminal.

57. 56. The battery of claim 55, wherein the weld hole exposes a flat portion and an inner flange portion of the electrode terminal and the inner gasket.

58. 56. The battery of claim 38, wherein a first bus bar terminal is electrically coupled to a surface of the electrode terminal, and a second bus bar terminal is electrically coupled to an outer surface of the bottom of the battery housing.

59. the first bus bar terminals overlap the electrode terminals in a plane to form a first overlapping region, and the second bus bar terminals overlap the outer surface of the bottom of the battery housing in a plane to form a second overlapping region; The diameter of the electrode terminal and the width of the outer surface of the bottom of the battery housing satisfy the following formula 1: [Formula 1] W １ ≦E １ ≦D-2R ｄ -2G-2W ２ E ２ =0.5×(D-2R) ｄ -2G-E １ ) E １ is the diameter of the outer flange portion of the electrode terminal, and E ２ is the width of the exposed surface of the outer surface of the bottom of the battery housing that is parallel to the surface of the electrode terminal, D is the outer diameter of the battery housing, and R ｄ is the width of the rounded area of ​​the battery housing periphery measured on a flat surface, G is the exposed width of the outer gasket through the periphery of the electrode terminal, and W １ is the maximum distance between any two points selected at the ends of the first overlapping region, and W ２ 59. The battery of claim 58, wherein is the maximum distance between two points where a plurality of straight lines passing through the center of the electrode terminal intersect with the end of the second overlapping region.

60. 60. The battery of any one of claims 38 to 59, wherein the battery has a form factor ratio of diameter divided by height greater than 0.

4.

61. 61. A battery pack comprising a plurality of batteries according to any one of claims 38 to 60.

62. The plurality of batteries are arranged in a predetermined number of rows; 62. The battery pack of claim 61, wherein the electrode terminals of each of the plurality of batteries and the outer surface of the bottom of the battery housing are arranged facing upward.

63. A plurality of bus bars are included which connect the plurality of batteries in series and in parallel, the plurality of bus bars are disposed on top of the plurality of batteries; Each of the plurality of bus bars is a body portion extending between the electrode terminals of adjacent batteries; a plurality of first bus bar terminals extending to one side of the body portion and electrically coupled to the electrode terminals of the battery located on the one side; 63. The battery pack of claim 62, further comprising: a plurality of second bus bar terminals extending to the other side of the body portion and electrically coupling to an outer surface of the bottom of the cell housing of a battery located on the other side.

64. 64. The battery pack of any one of claims 61 to 63, wherein the AC resistance measured between the electrode terminals of the battery and the outer surface of the bottom of the battery housing is 4 mΩ or less.

65. 65. A motor vehicle comprising at least one battery pack according to any one of claims 61 to 64.

66. a body portion including an upper surface, a lower surface, and an outer surface; an external flange portion extending from the outer surface of the main body portion along the outer surface of the bottom of the battery housing; an inner flange portion extending from an outer surface of the body portion toward an inner surface of the bottom portion of the battery housing; an exposed surface of the external flange portion facing the lower surface of the main body portion and the outer surface of the bottom of the battery housing forms an electrical contact surface that extends continuously from the center of the lower surface of the main body portion to the periphery of the exposed surface of the external flange portion; The electrode terminal has an upper surface of the main body connected to a current collector.

67. 67. The electrode terminal according to claim 66, wherein an upper surface of the main body portion is located above the inner flange portion.

68. 68. The electrode terminal according to claim 66 or 67, wherein the upper surface of the main body portion is flat.

69. 69. The electrode terminal of any one of claims 66 to 68, wherein a groove is provided between the body portion and the inner flange portion.

70. 70. The electrode terminal of claim 69, wherein the groove includes a first surface formed by an outer surface of the body portion and a second surface formed by an upper surface of the inner flange portion.

71. 71. The electrode terminal according to claim 70, wherein the first surface and the second surface are asymmetric.

72. 72. The electrode terminal according to any one of claims 66 to 71, wherein an angle between the inner flange portion and the outer flange portion is between 0° and 60°.

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