Battery, battery pack and vehicle comprising same

Abstract

Provided is a battery comprising: a battery housing that includes a sidewall portion, a bottom portion connected to one end of the sidewall portion in an axial direction, and an open end portion provided at the other end of the sidewall portion in the axial direction; an electrode assembly in which a first electrode, a second electrode, and a separator interposed therebetween are wound about a winding axis, wherein a tab of the second electrode is accommodated inside the battery housing so as to face the open end portion; and a lead that covers the open end portion of the battery housing and is electrically connected to the second electrode. A first inclined portion is formed at the other end of the sidewall portion in the axial direction such that the inner diameter of the battery housing increases going outward in the axial direction, an abutting surface is formed on the outer circumferential surface of the lead such that the outer diameter thereof increases going outward in the axial direction, and at least a portion of the abutting surface and the first inclined portion are in contact with and coupled to each other.

Description

Batteries, battery packs containing the same, and vehicles

[0001] The present invention relates to a battery, a battery pack including the same, and a vehicle.

[0002] This application claims the benefit of priority to Korean Patent Application No. 10-2024-0091338, filed July 10, 2024, and Korean Patent Application No. 10-2025-0087099, filed June 30, 2025, the entire contents of which are incorporated herein by reference.

[0003]

[0004] Secondary batteries, which have high applicability according to product group and electrical characteristics 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 power sources.

[0005] These secondary batteries are attracting attention as a new energy source for environmental friendliness and energy efficiency because they not only have the primary advantage of drastically reducing the use of fossil fuels, but also have the advantage of producing no byproducts from energy use.

[0006] Commonly used types of secondary batteries today include lithium-ion batteries, lithium polymer batteries, nickel-cadmium batteries, nickel-metal hydride batteries, and nickel-zinc batteries. The operating voltage of these unit secondary battery cells ranges from approximately 2.5 V to 4.5 V.

[0007] Therefore, when a higher output voltage is required, multiple battery cells are connected in series to form a battery module or battery pack. Furthermore, depending on the required charge / discharge capacity, a number of battery cells are connected in parallel to form a battery module or battery pack. Accordingly, the number and electrical connection configuration of battery cells included in a battery module or battery pack can be varied depending on at least one of the required output voltage and charge / discharge capacity.

[0008] Known battery cell types include cylindrical, prismatic, and pouch-shaped battery cells. Cylindrical batteries are constructed by interposing a separator, an insulator, between the positive and negative plates, then winding the separator to form a jelly-roll-shaped electrode assembly. This assembly, along with an electrolyte, is then inserted into the battery housing to form the cell.

[0009] In one embodiment, one side of the battery housing of a cylindrical battery may be open, and a lid may be welded to one side of the battery housing. However, if the area of ​​contact between the battery housing and the lid is insufficient, the weldability between the battery housing and the lid may be reduced, resulting in reduced weld strength or increased product defects such as electrolyte leakage.

[0010] Recently, seam welding has been studied as a method of joining leads and battery housings, replacing bead and crimping methods. This seam welding process involves welding the battery housing and the lead, assembling and welding the inner surface of the sidewall of the battery housing with the outer surface of the lead. To enhance the strength of the seam welding process, the contact area between the battery housing and the lead must be wide, minimizing the gap between the lead and the battery housing.

[0011]

[0012] The purpose of the present invention is to provide a welding structure of a battery housing and a lead capable of maximizing the contact area between the battery housing and the lead, and a battery using the welding structure.

[0013] In addition, the purpose is to provide a new shape of a forced fit structure that can increase the contact area between the battery housing and the lead and improve welding strength, and a battery using the same.

[0014] In addition, another purpose is to provide a battery that can secure the reliability of electrical connection while omitting the collector plate in the connection between the electrode assembly, the battery housing, and the electrode terminal by allowing the lead to perform the role of a collector plate.

[0015] In addition, the purpose is to provide an economical battery that can simplify the manufacturing process and reduce manufacturing costs by omitting the collector plate.

[0016] Furthermore, another object of the present invention is to provide a cylindrical battery and a battery pack and a vehicle including the same, which can reduce product defects caused by a decrease in welding strength or leakage of electrolyte.

[0017] Meanwhile, the technical problem to be solved by the present invention is not limited to the above purpose, and also includes other problems that can be clearly understood by those skilled in the art from the detailed description of the specification.

[0018]

[0019] To achieve this purpose, according to one aspect of the present invention, a battery of the following embodiment, a battery pack including the same, and a vehicle are provided.

[0020] According to a first embodiment, a battery is provided, comprising: a battery housing having a side wall portion, a bottom portion connected to one axial end of the side wall portion, and an open end provided at the other axial end of the side wall portion; an electrode assembly in which a first electrode, a second electrode, and a separator interposed therebetween are wound around a winding axis, and a tab of the second electrode is accommodated inside the battery housing so as to face the open end; and a lead covering the open end of the battery housing and electrically connected to the second electrode; wherein a first inclined portion is formed at the axial other end of the side wall portion so that an inner diameter of the battery housing widens in an axial outward direction, and an outer circumferential surface of the lead is formed so that an outer diameter thereof widens in an axial outward direction, and at least a portion of the abutment surface and the first inclined portion are in contact with each other and coupled.

[0021] According to a second embodiment, in the first embodiment, the mating surface of the lead and the first inclined portion of the battery housing may be fitted together without a gap.

[0022] According to a third embodiment, in any one of the first to second embodiments, the inclination of the mating surface and the inclination of the first inclined portion based on a cross-section parallel to the axial direction may be substantially the same.

[0023] According to a fourth embodiment, in any one of the first to third embodiments, the mating surface may have an inclination of 1° to 45° with respect to the axial direction based on a cross-section parallel to the axial direction.

[0024] According to a fifth embodiment, in any one of the first to fourth embodiments, the mating surface of the lead and the first inclined portion of the battery housing may be welded to form a welded portion.

[0025] According to the sixth embodiment, in the fifth embodiment, the welded portion may be formed with an area of ​​90% to 100% based on 100% of the area of ​​the first inclined portion.

[0026] According to the seventh embodiment, in any one of the first to sixth embodiments, the mating surface of the lead may include a mating inclined surface and a mating vertical surface.

[0027] According to an eighth embodiment, in any one of the first to seventh embodiments, the battery housing may be connected to the first inclined portion and have a horizontal portion perpendicular to the axial direction, and the horizontal portion may have substantially no step at a portion in contact with the outer surface of the lead.

[0028] According to the ninth embodiment, in any one of the first to eighth embodiments, the first inclined portion may be formed by a trimming process of the battery housing.

[0029] According to a tenth embodiment, in any one of the first to ninth embodiments, the lead may have an electrode connection portion electrically connected to the tab of the second electrode.

[0030] According to the 11th embodiment, in the 10th embodiment, the electrode connection portion may be provided at a position that is recessed axially inward from the radially inner side relative to the mating surface.

[0031] According to the 12th embodiment, in any one of the 10th to 11th embodiments, the electrode connecting portions may be arranged at equal intervals in the circumferential direction.

[0032] According to the 13th embodiment, in any one of the first to twelfth embodiments, the lead may include a vent portion.

[0033] According to the 14th embodiment, in any one of the first to 13th embodiments, a liquid injection port may be provided in the center of the lead.

[0034] According to a fifteenth embodiment, in any one of the first to fourteenth embodiments, the bottom of the battery housing may be provided with a first electrode terminal that is electrically insulated from and fixed to the bottom, and the first electrode of the electrode assembly may be electrically connected to the first electrode terminal.

[0035] According to a 16th embodiment, a battery pack is provided including a battery according to any one of the 1st to 15th embodiments.

[0036] According to a seventeenth embodiment, a vehicle is provided including a battery pack according to the sixteenth embodiment.

[0037]

[0038] A battery according to one aspect of the present invention can improve welding strength and enhance durability and reliability of the product by maximizing the contact area between the battery housing and the lead.

[0039] In addition, a battery according to one aspect of the present invention can increase the contact area and more effectively secure welding strength through a new shape of the forced fit structure of the battery housing and the lead.

[0040] In addition, a battery according to one aspect of the present invention can ensure reliability of electrical connection between an electrode assembly and a battery housing while omitting a separate current collector plate since the lead can serve as a current collector plate.

[0041] Accordingly, the battery according to one aspect of the present invention can simplify the structure by omitting the current collector plate, simplify the manufacturing process, and reduce manufacturing costs.

[0042] In addition, the battery according to one aspect of the present invention can reduce product defects caused by a decrease in welding strength or leakage of electrolyte, thereby improving the overall product quality.

[0043] Furthermore, the battery according to one aspect of the present invention can improve the quality and safety of not only a cylindrical battery but also a battery pack and a vehicle including the cylindrical battery based on these effects.

[0044] However, the effects that can be obtained through the present invention are not limited to the effects described above, and other technical effects that are not mentioned can be clearly understood by those skilled in the art from the description of the invention described below.

[0045] The following drawings attached to this specification illustrate preferred embodiments of the present invention, and serve to further understand the technical idea of ​​the present invention together with the contents of the invention described above, and therefore the present invention should not be interpreted as being limited to matters described in such drawings.

[0046] Figure 1a schematically illustrates the appearance of a battery according to one embodiment of the present invention.

[0047] Figure 1b schematically illustrates a process in which a first inclined portion is formed by trimming with a die and a punch when trimming the open end side of a battery housing.

[0048] Figure 2 schematically illustrates an exploded perspective view of an electrode assembly according to one embodiment of the present invention.

[0049] Figure 3 schematically illustrates a laminate of an electrode assembly according to one embodiment of the present invention.

[0050] FIG. 4 schematically illustrates an electrode assembly manufactured by winding a laminate of electrode assemblies in a jelly-roll shape according to one embodiment of the present invention.

[0051] FIG. 5 schematically illustrates an electrode assembly manufactured by winding a laminate of electrode assemblies in a jelly-roll shape according to one embodiment of the present invention.

[0052] FIG. 6 is a schematic diagram of a jelly-roll-shaped electrode assembly according to one embodiment of the present invention, in which a collector plate is attached to one surface and not attached to the other surface.

[0053] FIG. 7 is a schematic diagram illustrating a jelly-roll-shaped electrode assembly according to one embodiment of the present invention, in which a current collector is attached to one surface and not attached to the other surface.

[0054] Figure 8 schematically illustrates a process of storing an electrode assembly according to one embodiment of the present invention in a battery housing.

[0055] Figure 9 schematically illustrates a form in which a lead according to one embodiment of the present invention is coupled to a battery housing.

[0056] FIG. 10a is a schematic enlarged view of a joint portion of a lead coupled to a battery housing according to one embodiment of the present invention.

[0057] FIG. 10b is a schematic enlarged view of a joint portion of a lead coupled to a battery housing according to another embodiment of the present invention.

[0058] Figure 11 schematically illustrates a plug coupled to a lead according to one embodiment of the present invention.

[0059] Figure 12 schematically illustrates a battery pack according to one embodiment of the present invention.

[0060] Figure 13 schematically illustrates a vehicle according to one embodiment of the present invention.

[0061]

[0062] Terms or words used in this specification and claims should not be interpreted as limited to their usual or dictionary meanings, but should be interpreted as meanings and concepts that conform to the technical idea of ​​the present invention, based on the principle that the inventor can appropriately define the concept of the term to explain his or her own invention in the best way.

[0063] The terminology used herein is for the purpose of describing exemplary embodiments only and is not intended to limit the present invention. Singular expressions include plural expressions unless the context clearly dictates otherwise.

[0064] Justice

[0065] Throughout this specification, whenever a part is said to "include" a component, this does not mean that it excludes other components, but rather that it may include other components, unless otherwise specifically stated.

[0066] Throughout this specification, unless otherwise specifically stated, each component may be singular or plural.

[0067] Throughout this specification, any configuration being disposed "on (or below)" a component or "on (or below)" a component may mean not only that any configuration is disposed in contact with the upper surface (or lower surface) of said component, but also that other configurations may be interposed between said component and any configuration disposed on (or below) said component.

[0068] Throughout this specification, whenever a component is described as being "connected," "coupled," or "connected" to another component, it should be understood that the components may be directly connected or connected to one another, but that other components may also be "interposed" between the components, or that each component may be "connected," "coupled," or "connected" through another component.

[0069] Throughout this specification, when we refer to "A and / or B", this means A, B, or A and B, unless otherwise stated, and when we refer to "C to D", this means C or more and D or less, unless otherwise stated.

[0070] Throughout the present specification, the term “axial direction” refers to the axial direction in which the axis forming the winding center of the jelly-roll-shaped electrode assembly extends, the term “radial direction” refers to the direction toward or away from the winding axis, and the term “circular direction” refers to the direction surrounding the axis.

[0071] The embodiments described in this specification and the configurations illustrated in the drawings are only the most preferred embodiments of the present invention and do not represent all of the technical ideas of the present invention. Therefore, it should be understood that there may be various equivalents and modified examples that can replace them at the time of filing this application.

[0072]

[0073] The present invention provides a battery (1).

[0074] The battery of the present invention may be, for example, a cylindrical battery having a form factor ratio (defined as the ratio of the diameter (Φ) to the height (H) of the cylindrical battery divided by the height) of approximately 0.4 or greater.

[0075] Here, the form factor refers to a value indicating the diameter and height of a cylindrical battery. Cylindrical batteries applicable to a pressure tester may be, for example, 46110 cells, 48750 cells, 48110 cells, 48800 cells, or 46800 cells. In the numerical value indicating the form factor, the first two numbers indicate the diameter of the cell, the next two numbers indicate the height of the cell, and the final number 0 indicates that the cross-section of the cell is circular.

[0076] The battery to be applied to the pressure tester may be a cylindrical battery having a roughly cylindrical shape, a diameter of approximately 46 mm, a height of approximately 110 mm, and a form factor ratio of 0.418.

[0077] In another embodiment, the battery may be a cylindrical battery having a generally cylindrical cell shape, a diameter of approximately 48 mm, a height of approximately 75 mm, and a form factor ratio of 0.640.

[0078] According to another embodiment, the battery may be a cylindrical battery having a generally cylindrical cell shape, a diameter of approximately 48 mm, a height of approximately 110 mm, and a form factor ratio of 0.418.

[0079] According to another embodiment, the battery may be a cylindrical battery having a cell having a generally cylindrical shape, a diameter of approximately 48 mm, a height of approximately 80 mm, and a form factor ratio of 0.600.

[0080] According to another embodiment, the battery may be a cylindrical battery having a cell having a generally cylindrical shape, a diameter of approximately 46 mm, a height of approximately 80 mm, and a form factor ratio of 0.575.

[0081] The pressure tester of the present invention can of course be applied to battery cells having a form factor ratio of approximately 0.4 or less, such as 18650 cells, 21700 cells, etc. For 18650 cells, the diameter is approximately 18 mm, the height is approximately 65 mm, and the form factor ratio is 0.277. For 21700 cells, the diameter is approximately 21 mm, the height is approximately 70 mm, and the form factor ratio is 0.300.

[0082] Referring to FIG. 1, the battery housing (10) of the present invention has a cylindrical side wall portion (11), a bottom portion (12) connected to one axial end of the side wall portion (11), and an open end provided at the other axial end of the side wall portion (11).

[0083] The above-mentioned bottom portion (12) and the side wall portion (11) can be manufactured by forming a conductive metal sheet using a deep drawing process, and trimming the front end of the side wall portion (11) with a punch while holding it with a blank holder.

[0084] Specifically, the battery housing (10) may have a shape having a cylindrical main body and a trimming portion that extends radially outwardly and is inclined toward the axial outer side by a deep drawing process of a steel plate.

[0085] Thereafter, as in Fig. 1b, the can trimming process can be performed by placing a die (D) on the outer surface of the battery housing and cutting with a punch (P). Specifically, the die (D) is placed on the outer surface of the battery housing, and a step portion (not shown) perpendicular to the side wall portion of the battery housing is formed on the inner surface of the battery housing, and then the trimming portion can be removed by cutting with a cutting means (not shown) provided on the punch (P), and in this process, a first inclined portion (111) can be formed on the inner surface of the battery housing. In this way, the first inclined portion (111) is formed on the other axial end of the side wall portion (11) so that the inner diameter of the battery housing widens in the axial outward direction.

[0086] In one embodiment of the present invention, the conductive metal sheet may include, but is not limited to, aluminum, steel, stainless steel, and the like.

[0087] In one embodiment of the present invention, the first inclined portion (111) may have a chamfer shape such as a chamfer or may be rounded.

[0088]

[0089] In one embodiment of the present invention, an electrode assembly (20) is accommodated within the battery housing (10). The electrode assembly (20) is manufactured in the form of a jelly-roll by preparing a first electrode (21), a second electrode (22), and a separator (28) that extend in the longitudinal direction with a predetermined width as illustrated in FIG. 2, and forming a laminate by sequentially stacking the first electrode (21), the separator (28), the second electrode (22), and the separator (28) as illustrated in FIG. 3, and then winding the laminate around a core shaft.

[0090] In one embodiment of the present invention, the first electrode (21) may be an anode, and the second electrode (22) may be a cathode. Of course, the opposite may also be the case.

[0091] In one embodiment of the present invention, the first electrode (21) and the second electrode (22) are manufactured in the form of sheets. The electrode sheet may be manufactured in the form of an active material layer (24) applied to the surface of a metal foil (23). The electrode sheet may have a holding portion (25) region where the active material layer (24) is applied, and a non-coated portion (26) region where the active material layer (24) is not applied. The positive electrode sheet may have a non-coated portion (26) region on one side in the width direction, and the negative electrode sheet may have a non-coated portion (26) region on the other side in the width direction.

[0092]

[0093] In one embodiment of the present invention, the positive electrode can be manufactured by coating a composition for forming a positive electrode including a positive electrode active material, a binder, a conductive agent, a solvent, etc. on a positive electrode current collector.

[0094] In one embodiment of the present invention, the cathode active material may be any conventional cathode active material that can be used in the cathode of a conventional electrochemical device. For example, the cathode active material may be lithium manganese oxide, lithium cobalt oxide, lithium nickel oxide, lithium iron oxide, or a lithium composite oxide comprising any of these.

[0095] At this time, the positive electrode active material may be included in an amount of 80 to 99 wt%, preferably 85 to 98 wt%, based on the total solid content of the composition for forming the positive electrode. When the content of the positive electrode active material satisfies the above-described range, excellent capacity characteristics can be exhibited.

[0096] The positive electrode current collector is not particularly limited as long as it is conductive and does not cause chemical changes in the battery. For example, the positive electrode current collector may be made of stainless steel, aluminum, nickel, titanium, calcined carbon, or aluminum or stainless steel surface-treated with carbon, nickel, titanium, silver, etc.

[0097] The above binder is a component that assists in the bonding of the active material and the conductive material and the bonding to the current collector, and can typically be added in an amount of 1 to 30 wt% based on the total solid weight of the composition for forming the positive electrode. Examples of such binders include polyvinylidene fluoride, polyvinyl alcohol, carboxymethyl cellulose (CMC), starch, hydroxypropyl cellulose, regenerated cellulose, polyvinylpyrrolidone, tetrafluoroethylene, polyethylene, polypropylene, ethylene-propylene-diene terpolymer (EPDM), sulfonated EPDM, styrene-butadiene rubber, fluororubber, various copolymers, etc.

[0098] The above-mentioned conductive agent can typically be added in an amount of 1 wt% to 30 wt% based on the total solid weight of the composition for forming the anode.

[0099] The conductive material is not particularly limited as long as it is conductive and does not cause a chemical change in the battery, and examples thereof include: graphite; carbon-based materials such as carbon black, acetylene black, Ketjen black, channel black, furnace black, lamp black, and thermal black; conductive fibers such as carbon fibers or metal fibers; metal powders such as fluorinated carbon, aluminum, and nickel powders; conductive whiskeys such as zinc oxide and potassium titanate; conductive metal oxides such as titanium oxide; and conductive materials such as polyphenylene derivatives. Specific examples of commercially available conductive agents include acetylene black series (Chevron Chemical Company, Denka Singapore Private Limited, Gulf Oil Company), Ketjenblack, EC series (Armak Company), Vulcan XC-72 (Cabot Company), and Super P (Timcal).

[0100] In addition, the positive electrode active material layer may optionally further include a dispersant as needed.

[0101] The above dispersant can be used without any special restrictions as long as it is used as a dispersant of the anode, and for example, an aqueous dispersant or an organic dispersant can be selectively used as needed. Preferably, the dispersant is a cellulose-based compound, polyalkylene oxide, polyvinyl alcohol, polyvinyl pyrrolidone, polyvinyl acetal, polyvinyl ether, polyvinyl sulfonic acid, polyvinyl chloride (PVC), polyvinylidene fluoride, chitosan, starch, amylose, polyacrylamide, poly-N-isopropylacrylamide, poly-N,N-dimethylacrylamide, polyethyleneimine, polyoxyethylene, poly(2-methoxyethoxyethylene), poly(acrylamide-co-diallyldimethylammonium chloride), acrylonitrile / butadiene / styrene (ABS) polymer, a mixture of acrylonitrile / styrene / acrylate (ASA) polymer and propylene carbonate, a styrene / acrylonitrile (SAN) copolymer, Examples thereof include methyl methacrylate / acrylonitrile / butadiene / styrene (MABS) polymers, styrene butadiene rubber, nitrile butadiene rubber, and fluoroelastomers, and any one or a mixture of two or more thereof may be used. Hydrogenated nitrile butadiene rubber (H-NBR) may be used. When the positive electrode active material layer further includes a dispersant, the dispersibility of the components of the positive electrode active material layer, particularly the conductive material, may be increased, but is not limited thereto.

[0102] In addition, the solvent may be a solvent generally used in the relevant technical field, such as dimethylsulfoxide (DMSO), isopropyl alcohol, N-methylpyrrolidone (NMP), acetone, or water, and one of these may be used alone or as a mixture of two or more. The amount of the solvent used is sufficient to dissolve or disperse the positive electrode active material, conductive material, and binder in consideration of the coating thickness and manufacturing yield of the slurry, and to have a viscosity that can exhibit excellent thickness uniformity when applied thereafter for manufacturing the positive electrode.

[0103] The negative electrode according to the present invention can be manufactured by coating a negative electrode forming composition including the above-described negative electrode active material, binder, conductive agent, solvent, etc. on a negative electrode current collector. In addition, the negative electrode forming composition may optionally further include a dispersant as needed.

[0104] As the negative electrode active material, a compound capable of reversible intercalation and deintercalation of lithium may be used. Preferably, the negative electrode is a silicon-based negative electrode active material, a carbon-based negative electrode active material, or Li that exhibits high-capacity characteristics. x Fe2O3(0≤x≤1), Li x WO2(0≤x≤1), Sn x Me 1-x Me' y O z(Me: Mn, Fe, Pb, Ge; Me': Al, B, P, Si, elements of group 1, 2, and 3 of the periodic table, halogens; 0 <x≤1; 1≤y≤3; 1≤z≤8) 등의 금속 복합 산화물; 리튬 금속; 리튬 합금; 주석계 합금; SnO, SnO2, PbO, PbO2, Pb2O3, Pb3O4, Sb2O3, Sb2O4, Sb2O5, GeO, GeO2, Bi2O3, Bi2O4, 및 Bi2O5등의 금속 산화물; 폴리아세틸렌 등의 도전성 고분자; Li-Co-Ni 계 재료; 티타늄 산화물; 리튬 티타늄 산화물 등의 음극 활물질을 더 사용할 수 있다. 상기 규소계 음극 활물질은 Si, SiOx(0.1<x<5), Si-금속 합금, Mg와 같은 금속이 도핑 또는 화학 결합된 실리콘 산화물 입자(SiOx, 0.1<x<5) 및 Si와 SiOx(0.1<x<5)의 합금으로 이루어진 군에서 선택된 하나 이상을 포함할 수 있다. 상기 탄소계 음극 활물질은 천연 흑연, 인조 흑연, 비정질 하드카본(hard carbon), 저결정질 소프트카본(soft carbon), 카본 블랙, 아세틸렌 블랙, 케첸 블랙, 수퍼 P, 그래핀 (graphene), 및 섬유상 탄소로 이루어진 군으로부터 선택되는 하나 이상을 포함할 수 있다.

[0105] The negative electrode current collector is not particularly limited as long as it has high conductivity without causing chemical changes in the battery, and for example, copper, stainless steel, aluminum, nickel, titanium, calcined carbon, copper or stainless steel surface-treated with carbon, nickel, titanium, silver, etc., aluminum-cadmium alloy, etc. can be used. In addition, the negative electrode current collector can typically have a thickness of 3 ㎛ to 500 ㎛, and like the positive electrode current collector, fine unevenness can be formed on the surface of the current collector to strengthen the bonding strength of the negative electrode active material. For example, it can be used in various forms such as a film, a sheet, a foil, a net, a porous body, a foam, a non-woven fabric, etc.

[0106] The conductive material, binder, solvent or dispersant included in the above-described composition for forming the cathode may be applied without any special limitation as long as it is generally usable in a composition for forming an electrode. For example, the conductive material, binder, solvent or dispersant described in the above-described composition for forming the anode may be applied.

[0107]

[0108] In one embodiment of the present invention, the non-conductive portion (26) region may be exposed or protruded in the width direction from the laminate as illustrated in FIGS. 2 and 3. The non-conductive portion (26) itself may function as an electrode tab.

[0109] In one embodiment of the present invention, the non-conductive portion (26) may be provided with notches at predetermined intervals to form flag-shaped notched tabs (27).

[0110] In one embodiment of the present invention, the notching tabs (27) may be in the shape of an equilateral trapezoid as illustrated in FIGS. 2 and 3. However, their shapes may be various shapes such as a semicircle, a semi-ellipse, a triangle, a rectangle, a parallelogram, etc.

[0111] In one embodiment of the present invention, the notched tabs (27) may have a shape having the same width arranged along the longitudinal direction. However, the width of the notched tabs may also be a shape that gradually or stepwise widens from the core side to the outer periphery side.

[0112] In one embodiment of the present invention, the height of the notching tabs (27) may gradually increase from the winding side toward the radial outer side. However, the heights of these notching tabs (27) may also be implemented in a form in which they are constant or gradually decrease.

[0113] In one embodiment of the present invention, the structure may be such that the notching tab (27) is omitted in a predetermined section of the radially inner end of the plain portion (26) and a predetermined section of the radially outer end. However, it goes without saying that the notching tab may not be deleted in the radially inner end of the plain portion, and the notching tab may not be deleted in the radially outer end of the plain portion.

[0114]

[0115] In one embodiment of the present invention, the notched tab (27) of the jelly-roll shaped electrode assembly (20) can be radially bent and flattened. The notched tab (27) can be bent radially inward or outward. For example, as illustrated in FIGS. 4 and 5, the notched tab (27) can be bent radially inward.

[0116] In one embodiment of the present invention, the notched tabs (27) may be bent one by one during the process of forming a jelly-roll-shaped electrode assembly (20) by winding the laminate. Alternatively, the notched tabs (27) may be bent all at once after the laminate is wound to form a jelly-roll-shaped electrode assembly.

[0117] In one embodiment of the present invention, the notched tabs (27) of the first electrode (21) and the notched tabs (27) of the second electrode (22), which are bent and overlapped in the radial direction, can provide a plane substantially perpendicular to the axial direction at both axial ends of the electrode assembly (20), as illustrated in FIG. 5.

[0118] In one embodiment of the present invention, a current collector plate (31) can be joined to a substantially flat surface provided by bending the notched tabs (27) exposed at both axial ends of the electrode assembly (20), as shown in FIG. 6.

[0119] In one embodiment of the present invention, the current collector (31) can be manufactured by punching, trimming, piercing, and bending a metal sheet.

[0120] In one embodiment of the present invention, referring to FIG. 6, the current collector plate (31) may be provided with a terminal connection portion (32) extending radially from the center, a ring portion (33) connecting the centrifugal edge of the terminal connection portion (32) in a circumferential direction, and an electrode connection portion (34) extending centripetally from the ring portion (33) but not connected to the terminal connection portion (32). The center of the terminal connection portion (32) may cover at least a portion of the core hollow portion of the electrode assembly (20).

[0121] In one embodiment of the present invention, the electrode connection portion (34) may be joined to the notched tab (27) of the first electrode (21) of the electrode assembly (20) by laser welding or the like before the electrode assembly (20) is placed in the battery housing (10).

[0122] In one embodiment of the present invention, referring to FIG. 7, a collector plate may not be connected to the notched tab (27) of the second electrode (22) of the electrode assembly (20). Of course, the present invention is not limited to a structure in which a collector plate is not connected to the notched tab (27) of the second electrode (22).

[0123] In one embodiment of the present invention, as illustrated in FIGS. 8 and 9, the electrode assembly (20) can be accommodated in the battery housing (10) in a state where the current collector (31) is aligned so as to face the bottom portion (12) of the battery housing (10). At this time, an insulator (16) may be interposed between the current collector (31) and the bottom portion (12) of the battery housing (10) so as to electrically insulate the current collector (31) from the bottom portion (12).

[0124] In one embodiment of the present invention, the terminal connection portion (32) of the current collector plate (31) can be joined to the first electrode terminal (13) fixed to the battery housing (10) by a method such as resistance welding, ultrasonic welding, or laser welding. A welding device for forming a weld portion between the current collector plate (31) and the first electrode terminal (13) can approach the back surface of the center of the terminal connection portion (32) of the current collector plate (31) through the core hollow portion of the electrode assembly (20) from the other axial end of the electrode assembly (20) to perform welding. Of course, in addition to this, the current collector plate (31) and the first electrode terminal (13) can also be joined by a brazing or soldering method. In other words, various methods can be applied to the current collector plate (31) and the first electrode terminal (13) as long as they can be electrically connected and fixed to each other.

[0125] In a state where the electrode assembly (20) is accommodated in the battery housing (10) and the first electrode (21) is connected to the first electrode terminal (13), the notched tab (27) of the second electrode (22) can be directly connected to the lead (40) that is press-fitted through the open end of the battery housing (10). Accordingly, the second electrode (22) is electrically connected through the welded portion of the notched tab (27) and the lead (40). Of course, other joining methods, such as brazing or soldering, can be applied to the notched tab (27) and the lead (40) in addition to the welding method.

[0126] In one embodiment of the present invention, the mating surface (41) of the lead is electrically connected to the side wall portion (11) of the battery housing by being joined and sealed. Accordingly, the second electrode (22) can be electrically connected to the lead (40) and the battery housing (10). Various methods, such as welding, brazing, and soldering, that enable electrical connection and sealing, can be applied to the processing of the joint portion (M) between the lead (40) and the battery housing (10).

[0127]

[0128] In one embodiment of the present invention, the lead (40) can be manufactured by pressing and forming a circular metal sheet.

[0129] In one embodiment of the present invention, the lead (40) has a substantially disc shape so as to block the open end of the battery housing (10).

[0130] As described above, when the battery housing (10) is manufactured by a trimming process, a first inclined portion (111) is formed on the other end of the axial wall portion so that the inner diameter of the battery housing increases in the axial outward direction. In this case, if the contact area between the lead (40) and the battery housing is insufficient, even if the connection is made through welding, the welding strength may be low, the electrolyte may leak, or the mechanical strength of the battery may be weak. Accordingly, even if the first inclined portion (111) is formed on the other end of the side wall portion (11), a joining structure capable of forming a sufficient contact area with the lead (40) and a battery including the same are required.

[0131] The outer surface of the above lead (40) is formed with a mating surface (41) so that the outer diameter or radial circumference widens axially outward. At least a portion of the mating surface (41) and the first inclined portion (111) of the battery housing are in contact and joined.

[0132] Referring to Fig. 10a, the combination of the battery housing (10) and the lead (40) is specifically illustrated. The mating surface (41) of the lead and the first inclined portion (111) of the battery housing may be fitted together without any gap. Meanwhile, even if the battery housing (10) and the lead (40) are combined, the external shape of the battery housing (10) or the lead (40) may not change.

[0133] In one embodiment of the present invention, the gap between the first inclined portion (111) of the battery housing and the lead (40) may be substantially non-existent. In this case, the meaning of “substantially” may mean a difference in error of a measuring device when measuring the gap between the lead (40) and the side wall portion (11). For example, the gap between the abutment surface (41) and the first inclined portion (111) may be less than 10%, less than 9%, less than 8%, less than 7%, less than 6%, less than 5%, less than 4%, less than 3%, less than 2%, less than 1%, or may be in complete contact with the thickness of the first inclined portion (111).

[0134] In one embodiment of the present invention, the inclination of the abutment surface (41) and the inclination of the first inclined portion (111) based on a cross-section parallel to the axial direction may be substantially the same. At this time, the meaning of "substantially" may mean less than the error difference of the measuring device when measuring the angle formed by the axial direction based on a cross-section parallel to the axial direction of the lead (40) and the side wall portion (11). For example, as illustrated in FIG. 10A, the abutment surface (41) and the first inclined portion (111) may form an angle θ with the axial direction, and the angle θ may be substantially the same. In this case, the contact area between the abutment surface (41) and the first inclined portion (111) may be wider.

[0135] In one embodiment of the present invention, the mating surface may have an inclination of 1° to 45° with respect to the axial direction based on a cross-section parallel to the axial direction. That is, the angle θ between the mating surface (41) and the first inclined portion (111) and the axial direction may be within a range of 1° to 45°. In this case, the lead (40) may be stably seated on the battery housing (10) to cover the open end, and the electrolyte sealing property may be further improved.

[0136] In another embodiment of the present invention, the mating surface (41) of the lead may have a mating inclined surface (411) connected to the outer surface of the lead (40), as shown in FIG. 10b, and a mating vertical surface (412) connecting the mating inclined surface (411) and the inner surface of the lead (40).

[0137] At this time, the mating inclined surface (411) can be combined by contacting the first inclined portion (111), and the mating vertical surface (412) can be in contact with the inner surface of the side wall portion (11) connected to the first inclined portion (111).

[0138] In this way, since the lead (40) has a mating inclined surface (411) and a mating vertical surface (412), it can be complementarily combined with the side wall portion (11) to further enhance the sealing performance of the battery. In addition, since the lead (40) and the battery housing (10) are stably combined at a specific location, the pressing depth of the lead (40) can be maintained more consistently.

[0139] In one embodiment of the present invention, the mating surface (41) of the lead and the first inclined portion (111) of the battery housing may be welded to form a welded portion. The welding may include laser welding, ultrasonic welding, CO2 welding, etc.

[0140] In one embodiment of the present invention, the welded portion may be formed with an area of ​​90% to 100% based on 100% of the area of ​​the first inclined portion (111). The surface area of ​​the abutment surface (41) may be larger than the area of ​​the first inclined portion (111), and joining may be performed while the abutment surface (41) covers most of the surface area of ​​the first inclined portion (111).

[0141] In one embodiment of the present invention, the battery housing (10) may be connected to the first inclined portion (111) and may have a horizontal portion (112) that is perpendicular to the axial direction. The horizontal portion (112) may have substantially no step at a portion in contact with the outer surface of the lead (40). In other words, the horizontal portion (112) and the outer surface of the lead (40) may have the same height from the notched tab (27) of the electrode assembly (20). In this case, when the other end of the battery is used as the bottom in the battery pack, the contact area with the battery pack housing is large, so that heat exchange, etc., may be excellent.

[0142] In one embodiment of the present invention, the lead (40) may have a cross-sectional shape parallel to the axial direction that is asymmetrical with respect to the radially inner center, as shown in FIG. 9.

[0143] That is, the lead (40) may include a mating surface (41), an electrode connection portion (42), a flat portion (43), a bridge (44), and a support surface (45) from the radially outer side.

[0144] In one embodiment of the present invention, the support surface (45) may be formed to extend horizontally inwardly in a radial direction from the mating surface (41). Since the outer surface of the support surface (45) has a flat plane shape, when the battery is placed so that the lead (40) is placed on the floor, it can function as a foot of the battery.

[0145] In one embodiment of the present invention, the support surface (45) may have the same height as the horizontal portion (112) of the battery housing. That is, the support surface (45) may have the same height from the notched tab (27) of the electrode assembly.

[0146] In one embodiment of the present invention, an electrode connection portion (42) extending horizontally in the radial direction may be provided radially inward from the support surface (45) of the lead (40). Referring to Fig. 9, the electrode connection portion (42) may be provided at a position recessed axially inward.

[0147] In one embodiment of the present invention, the depth of the press-in of the lead (40) into the battery housing (10) may be determined by the electrode connection portion (42) of the lead (40) and the tab connection portion of the second electrode (22) of the electrode assembly (20) accommodated in the battery housing (10). That is, the bottom surface of the electrode connection portion (42) may be provided closest to the electrode assembly (20) than the remaining bottom surface of the lead (40). In this case, when the electrode connection portion (42) is coupled with the electrode assembly (20), the remaining portion of the lead (40) excluding the electrode connection portion (42) may be spaced apart from the electrode assembly (20).

[0148] In one embodiment of the present invention, the electrode connection portion (42) can be in close contact with the tab of the second electrode (22) of the electrode assembly (20), and they can be joined to each other. The joining thereof can be achieved by welding. The weld portion (W) of the electrode connection portion (42) and the notched tab (27) of the second electrode (22) can be formed by a laser irradiating the axial outer surface of the electrode connection portion (42) from the axial outer side as illustrated in FIG. 9. The laser can be irradiated in a scan manner along the radial direction to form a weld portion (W) that extends long in the radial direction. The electrode connection portion (42) can be joined face-to-face with the electrode assembly (20). The electrode connection portion (42) can be joined with the metal foil (23).

[0149] In this way, the lead (40) functions as a cover that closes the open end of the battery housing (10), while also functioning as a collector plate for the second electrode (22). Accordingly, the lead (40) can have a second polarity, and the side wall portion (11) welded thereto and the bottom portion (12) connected thereto can also have a second polarity.

[0150] In one embodiment of the present invention, the electrode connection portion (42) may extend radially outward by at least half the radius of the battery housing (10). Preferably, the electrode connection portion (42) may extend by at least 0.7 times the radius of the battery housing (10). The electrode connection portion (42) may extend radially flat.

[0151] In one embodiment of the present invention, the electrode connection portion (42) may occupy 50% or more of the total area of ​​the battery housing (10).

[0152] In one embodiment of the present invention, the electrode connection portion (42) of the lead (40) can have a flat, extended bottom shape with sufficient width, so that a welding area with the tab of the second electrode (22) can be sufficiently secured.

[0153] In one embodiment of the present invention, a current collector plate may be joined to the tab of the second electrode (22) and electrically connected, and the electrode connection portion (42) may be joined to the current collector plate and electrically connected to the tab of the second electrode (22). That is, a current collector plate may be welded to the tab of the second electrode (22), and the electrode connection portion (42) of the lead (40) may be welded to the current collector plate (31).

[0154] In another embodiment of the present invention, the electrode connecting portion (42) may be electrically connected by being directly bonded to the tab of the second electrode (22).

[0155] Specifically, it may have a structure in which the tab of the second electrode (22) is welded and electrically connected to the electrode connection portion (42) of the lead (40) without a separate collector plate. That is, since the lead (40) can be coupled to the battery housing (10) to cover the open end of the battery housing (10) and at the same time be electrically connected to the electrode assembly (20), a separate collector plate, for example, a negative collector plate, may not be provided. That is, the lead (40) of the present invention can be provided as a so-called integrated lead that can also perform the function of a collector plate. Accordingly, the joining portion of the lead (40) and the battery housing (10) is simplified, and there is no need to use the collector plate (31) when electrically connecting the electrode assembly (20) to the lead (40), thereby reducing the number of parts and assembly work, securing more internal volume, and further increasing the energy density.

[0156] In one embodiment of the present invention, the joining portion of the electrode connection portion (42) and the tab of the second electrode (22) may extend radially. That is, the electrode connection portion (42) may extend toward the flat portion (43) and the support surface (45). Specifically, the electrode connection portion (42) may extend centripetally toward the flat portion (43), and the electrode connection portion (42) may extend radially toward the support surface (45). In this case, since the length of the welding length (LFW, Lid Foil tab Welding) between the electrode connection portion (42) and the metal foil (23) can be secured long, the internal resistance of the battery cell can be reduced.

[0157] In one embodiment of the present invention, the electrode connecting portions (42) are plural in number and can be arranged radially with respect to the center of the lead (40) and can be arranged at equal intervals in the circumferential direction.

[0158] In one embodiment of the present invention, the electrode connecting portions (42) may be provided in three pieces at intervals of 120°.

[0159] In one embodiment of the present invention, the electrode connecting portion (42) may be provided in three pieces. When the electrode connecting portion (42) is provided in three pieces, a plurality of electrode connecting portions (42) can form a single plane, so that a stable flatness with the electrode assembly (20) can be more easily secured. In addition, the lead (40) locally contacts only the welding position of the notched tab (27) of the second electrode to secure adhesion, and the bulging resistance of the lead (40) due to the internal pressure of the battery cell can be secured.

[0160] In one embodiment of the present invention, the lead (40) may further include at least one bridge (44). The bridges (44) may be provided in multiple numbers, for example, three. The bridges (44) may extend radially from the flat portion (43). The bridges (44) may be formed to partition two adjacent electrode connection portions (42). The bridges (44) may extend from the flat portion (43) toward the mating surface (41).

[0161] In one embodiment of the present invention, a plurality of electrode connection portions (42) can be more securely separated and partitioned by the bridge (44). In this way, the bridge (44) can reinforce the rigidity of the lead (40).

[0162] In one embodiment of the present invention, the upper surface of the bridge (44) may be formed axially outer than the upper surface of the electrode connection portion (42), but axially inner than the upper surface of the flat portion (43). When the bridge (44) is formed in this manner, the rigidity of the lead (40) can be further reinforced.

[0163] In one embodiment of the present invention, the protruding height of the bridge (44) may correspond to or be lower than the protruding height of the support surface (45).

[0164] In one embodiment of the present invention, the protruding height of the bridge (44) corresponds to the protruding height of the support surface (45), so that they can form a single plane. In this case, when the battery housing (10) is placed upright so that the lead (40) of the battery housing (10) faces the floor, the bridge (44) can also come into contact with the floor together with the support surface (45).

[0165] In one embodiment of the present invention, if the height of the bridge (44) is lower than the support surface (45), the support surface (45) can provide an annular support surface.

[0166]

[0167] In one embodiment of the present invention, the lead (40) of the present invention may further include a liquid filler port (46) at the center of the lead (40). In a state where the open end of the battery housing (10) is covered with the lead (40), the liquid filler port (46) may be aligned with the core hollow portion of the electrode assembly (20) accommodated in the battery housing (10).

[0168] In one embodiment of the present invention, the injection port (46) may be provided on the bottom surface of the lead (40), i.e., on a flat portion (43) that protrudes axially outward from the electrode connection portion (42) of the lead (40), as illustrated in FIG. 9 and the like. The height of the flat portion (43) may be lower than the height of the support surface (45). The flat portion (43) may be connected to the centric edge of the electrode connection portion (42) and has a shape that extends axially outward as it goes radially inward.

[0169] In one embodiment of the present invention, the injection port (46) may be closed by covering a plug (50) as illustrated in FIG. 11, etc. The rim of the plug (50) may be sealed with the rim of the injection port (46). The sealing may be achieved by seam welding or by applying various other known sealing methods.

[0170] In one embodiment of the present invention, the plug (50) may be in the form of a plug and may be formed by deep drawing a thin metal sheet of 0.3 mm.

[0171] In one embodiment of the present invention, when the plug (50) is closed and covered over the injection port (46), the height of the plug (50) may also be lower than the height of the support surface (45). Since the plug (50) is also positioned lower than the support surface (45), even when the battery cell is erected so that the lead (40) touches the ground, the plug (50) may not receive a direct load.

[0172] In one embodiment of the present invention, the flat portion (43) protrudes axially outwardly higher than the bottom of the lead, i.e., the electrode connection portion (42). Accordingly, the edge portion of the injection port (46) is spaced apart from the notched tab (27) of the second electrode (22). Therefore, when the electrolyte is injected through the injection port (46), and the plug (50) is covered with the injection port (46) and joined by welding or other methods, the heat of the joining is transferred to the electrode assembly (20), thereby damaging the separator, and the impact of the finishing joining process of the plug (50) on the performance of the battery can be minimized.

[0173] Meanwhile, in another embodiment of the present invention, the lead (40) may not include a separate liquid filling port. In this case, when manufacturing a battery cell, if there is no separate liquid filling port, such as in the bottom portion (12) of the battery housing (10), the electrolyte filling process may be performed first before covering the battery housing (10) with the lead (40).

[0174] However, if the lead (40) further includes a liquid injection port (46), the electrolyte can be injected through the liquid injection port (46) even after the lead (40) is pressed into the battery housing (10) and the welding portion (W) and the joint portion (M) are formed. Then, compared to joining the lead (40) to the battery housing (10) in a liquid injection state, the joining heat can be prevented from affecting the electrolyte at all. In addition, when joining the cap (50) and the surrounding of the liquid injection port (46), since the flat portion (43) protrudes upward, the possibility that the joining heat of the cap (50) will affect the electrolyte can be reduced.

[0175] In one embodiment of the present invention, on the other hand, the injection hole (46) formed in the center of the lead (40) may be a passage through which a device for welding the first electrode terminal (13) and the current collector plate (31) of the first electrode (21) can pass.

[0176] Accordingly, even after the lead (40) is joined to the battery housing (10), it is possible to join the first electrode (21) and the first electrode terminal (13) by introducing the welding equipment into the battery housing (10) through the liquid injection port (46).

[0177] In one embodiment of the present invention, the flat portion (43) may further include a seating portion (43a) that is axially recessed inward and extends radially flat. In one embodiment of the present invention, due to the seating portion (43a), when welding the plug (50) to the injection port (46), interference of the electrolyte can be minimized.

[0178] In one embodiment of the present invention, the longer the length of the formed seating portion (43a) from the injection port (46) to the flat portion (43), the better the weldability with the plug (50).

[0179]

[0180] In one embodiment of the present invention, the vent portion (60) may be formed in the lead (40). The vent portion (60) may be ruptured by the internal pressure of high-temperature venting gas when a thermal event occurs in the battery cell, thereby allowing the venting gas to be discharged to the outside from the battery cell.

[0181] In one embodiment of the present invention, the lead (40) may be provided with a support surface (45) that extends radially flatly radially inward from the mating surface (41), the electrode connection portion (42) may be provided at an axially recessed position radially inward from the support surface (45), and the vent portion (60) may be provided on the support surface (45).

[0182] In one embodiment of the present invention, the vent portion (60) may be provided along the circumferential direction radially outside the electrode connection portion (42). The vent portion (60) may be implemented as a soft portion or a thin portion having both surfaces of the support surface (45) notched.

[0183] In one embodiment of the present invention, the strength of the vent part (60) is such that it does not deform under the force applied when the lead (40) is pressed into the battery housing (10), and when the internal pressure surges due to a short circuit or the like occurring inside the battery housing (10), it breaks and separates the electrode connection part (42) of the lead (40) and the mating surface (41) of the lead (40). Accordingly, the electrical connection between the electrode connection part (42) connected to the tab of the second electrode (22) and the battery housing (10) is severed, and the internal space of the battery housing (10) is opened to the outside, so that the gas that caused the internal pressure can be discharged.

[0184] In one embodiment of the present invention, the vent portion (60) may be provided near the center of the support surface (45). In this case, even if the support surface (45) is pressed, the pressing force is transmitted to the inclined surface connecting to the electrode connection portion (42) and does not affect the vent portion (60). Therefore, the force applied when joining the lead (40) to the battery housing (10) and the electrode assembly (20) may not deform the vent portion (60).

[0185] In one embodiment of the present invention, the vent portion (60) may be provided radially outside the bridge (44). And these bridges (44) may be provided between the electrode connection portions (42) in the circumferential direction.

[0186] In one embodiment of the present invention, therefore, when the internal pressure of the battery housing (10) increases, this pressure is smoothly transmitted to the lower space of the bridge (44) arranged between the electrode connecting portions (42) in the circumferential direction, and acts as a force that lifts the bridge (44) upward. In addition, this force is concentrated at three locations along the circumferential direction. Accordingly, the internal pressure of the battery housing (10) can be smoothly transmitted to the vent portion (60), thereby inducing smooth rupture of the vent portion (60).

[0187] In one embodiment of the present invention, the rupture pressure of the battery housing (10) can be controlled by controlling the vent part (60) and width, etc. For example, the vent part (60) can be controlled so that the pressure inside the battery housing (10) is 15 to 35 kgf / cm. 2It can be set to be ruptured when it is in the range of . The vent part (60) can be formed by notching to partially reduce the thickness of the lead (40). The vent part (60) can have a thickness gradient. The thickness gradient means that when checking the cross-section of the vent part (60), it is formed to be inclined at a certain angle with respect to a predetermined horizontal plane. Such a vent part (60) is ruptured when the pressure inside the battery housing (10) abnormally increases, thereby releasing all the gas inside to the outside.

[0188] In one embodiment of the present invention, a vent portion (60) may be provided in the form of a thin portion on the support surface (45). However, the vent portion (60) formed by the lid (40) is not limited thereto. For example, the vent portion may be provided in a cap (50) covering the liquid inlet (46), may be formed by a joint portion between the liquid inlet (46) and the cap (50), or may be formed by a joint portion (M) between the lid (40) and the battery housing (10).

[0189]

[0190] A hole is formed in the center of the bottom portion (12) of the battery housing, and a first electrode terminal (13) can be fitted into the hole. The first electrode terminal (13) can be fixed to the bottom portion (12) by being riveted while a terminal gasket (14) is interposed therebetween. The terminal gasket (14) is interposed between the first electrode terminal (13) and the bottom portion (12), thereby sealing the inside and outside of the battery housing (10) to prevent leakage of electrolyte, and electrically insulating the first electrode terminal (13) and the bottom portion (12).

[0191] However, the method of connecting the first electrode terminal (13) and the bottom part (12) is not limited to this. For example, if there is a structure that can seal between the first electrode terminal (13) and the bottom part (12) and electrically insulate the first electrode terminal (13) and the bottom part (12), various other fixing methods, such as a bolt-nut joint method, a glass seal method, or a chrome coating & PP-MAH thermal bonding method, can also be applied.

[0192] The first electrode terminal (13) may have a first polarity, and the battery housing (10) may have a second polarity. Accordingly, both the bottom portion (12) of the battery housing (10) and the side wall portion (11) connected thereto may have a second polarity.

[0193] Accordingly, the battery housing (10) may have both the first electrode terminal (13) and the second electrode terminal (15) positioned at one axial end. In this case, the battery housing (10) may have both the bus bar connected to the first electrode terminal (13) and the bus bar connected to the second electrode terminal (15) positioned at one axial end of the battery housing (10).

[0194] In one embodiment of the present invention, the first electrode terminal (13) may be a positive terminal, and the second electrode terminal (15) may be a negative terminal. Of course, the opposite may also be true.

[0195]

[0196] Referring to Fig. 12, a battery (1) to which the lead described above is applied can be accommodated in a housing (71) of a battery pack (70). The battery pack (70) may be configured using a battery module, which is an intermediate form of assembly, or the battery pack (70) may be configured directly without a battery module, as shown.

[0197] Since the battery (1) described above has a large volume in itself, there is no particular difficulty in implementing a battery pack (70) even without using an intermediate structure called a battery module. In addition, since the second electrode of the battery (1) is connected through a lead, the internal resistance can be low and the energy density can be higher. In addition, since the vent part (60) structure is provided in the lead (40) so that it does not occupy a separate space, the energy density can be further secured. Accordingly, the energy density of the battery pack (70) equipped with the battery (1) can be implemented to be higher.

[0198] A battery pack (70) with such a high energy density can store the same amount of energy while reducing its volume and weight. Therefore, when a battery pack (70) equipped with such a battery (1) is installed in a vehicle, such as an automobile (80) that uses electricity as its energy source, as illustrated in Fig. 13, the vehicle's mileage relative to its energy consumption can be further increased.

[0199] It should be understood that the above-described embodiments are illustrative in all respects and not restrictive, and the scope of the present invention will be determined by the claims that follow, rather than by the detailed description set forth above. Furthermore, the meaning and scope of the claims that follow, as well as all possible modifications and variations derived from their equivalent concepts, should be construed as encompassing the scope of the present invention.

[0200]

[0201] Although the present invention has been described above with reference to limited embodiments and drawings, the present invention is not limited thereto, and those skilled in the art to which the present invention pertains may make various modifications and variations within the scope of the technical spirit of the present invention and the equivalent scope of the claims to be described below. Therefore, the embodiments disclosed above should be considered in an illustrative rather than a restrictive sense. In other words, the true scope of the technical spirit of the present invention is set forth in the claims, and all differences within the scope of equivalents thereof should be construed as being included in the present invention.

[0202] Hereinafter, the present invention will be described in more detail through examples, but the following examples are intended to illustrate the present invention, and the scope of the present invention is not limited to these examples.

Claims

1. A battery housing having a side wall portion, a bottom portion connected to one axial end of the side wall portion, and an open end provided at the other axial end of the side wall portion; An electrode assembly in which a first electrode and a second electrode and a separator interposed therebetween are wound around a winding axis and the tab of the second electrode is accommodated inside the battery housing so that it faces the open end; and a lead covering the open end of the battery housing and electrically connected to the second electrode; A first inclined portion is formed on the axial other end of the side wall portion so that the inner diameter of the battery housing widens in the axial outward direction, The outer surface of the above lead is formed with a mating surface so that the outer diameter increases in the axial outer direction. A battery characterized in that at least a portion of the above mating surface and the first inclined portion are in contact and joined.

2. In claim 1, A battery characterized in that the mating surface of the lead and the first inclined portion of the battery housing are fitted together without any gap.

3. In claim 1, A battery characterized in that the slope of the mating surface and the slope of the first inclined portion are substantially the same based on a cross-section parallel to the axial direction.

4. In claim 1, A battery cell characterized in that the above mating surface has an inclination of 1° to 45° with respect to the axial direction based on a cross-section parallel to the axial direction.

5. In claim 1, A battery characterized in that the mating surface of the lead and the first inclined portion of the battery housing are welded to form a welded portion.

6. In claim 5, A battery characterized in that the above welding part is formed with an area of ​​90% to 100% based on 100% of the area of ​​the first inclined part.

7. In claim 1, A battery characterized in that the mating surface of the above lead includes a mating inclined surface and a mating vertical surface.

8. In claim 1, The above battery housing is connected to the first inclined portion and has a horizontal portion that is perpendicular to the axial direction, A battery characterized in that the horizontal portion has substantially no step at the part where it comes into contact with the outer surface of the lead.

9. In claim 1, A battery characterized in that the first inclined portion is formed by a trimming process of the battery housing.

10. In claim 1, A battery characterized in that the lead has an electrode connection portion electrically connected to the tab of the second electrode.

11. In claim 10, A battery characterized in that the electrode connection portion is provided at a position that is recessed axially inward from the radially inner side of the mating surface.

12. In claim 10, A battery characterized in that the electrode connecting portions are arranged at equal intervals in the circumferential direction.

13. In claim 1, A battery characterized in that the above lead includes a vent portion.

14. In claim 1, A battery characterized in that a liquid injection port is provided in the center of the above lead.

15. In claim 1, The bottom of the above battery housing is provided with a first electrode terminal that is electrically insulated from and fixed to the bottom, A battery, characterized in that the first electrode of the electrode assembly is electrically connected to the first electrode terminal.

16. A battery pack comprising the battery of any one of claims 1 to 15.

17. A vehicle comprising the battery pack of claim 16.

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