Battery, battery pack and vehicle comprising same

Abstract

The present invention provides a battery comprising: a battery housing having a side wall portion, a bottom portion connected to one end portion of the side wall portion in the axial direction, and an open end portion provided at the other end portion of the side wall portion in the axial direction; an electrode assembly in which a first electrode, a second electrode, and a separator interposed therebetween are wound around a winding axis, and which is accommodated in the battery housing such that a tab of the second electrode faces the open end portion; and a lid which covers the open end portion and is coupled to the battery housing, wherein an abutment portion is formed on a part of the inner surface of the other end portion of the side wall portion in the axial direction, and the outer circumferential surface of the lid and the abutment portion are 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. 10-2024-0092467, filed July 12, 2024, and Korean Patent Application No. 10-2025-0087112, 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] 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.

[0015] However, the technical problems to be solved by the present invention are not limited to the problems described above, and other problems not mentioned can be clearly understood by those skilled in the art from the description of the invention described below.

[0016]

[0017] 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.

[0018] 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 lid covering the open end and coupled with the battery housing, wherein a mating portion is formed on a portion of an inner surface of the other axial end of the side wall portion, and an outer circumferential surface of the lid and the mating portion are coupled.

[0019] According to a second embodiment, in the first embodiment, the abutting portion may be in contact with the outer surface of the lead by 40% or more based on a cross-section parallel to the axial direction and a height of 100% of the outer surface of the lead.

[0020] According to a third embodiment, in any one of the first to second embodiments, the abutment portion may be in contact with the outer surface of the lead for a length of 0.3 mm or more based on a cross-section parallel to the axial direction.

[0021] According to a fourth embodiment, in any one of the first to third embodiments, the height of the outer surface of the lead may be 0.5 mm to 0.8 mm based on a cross-section parallel to the axial direction.

[0022] According to a fifth embodiment, in any one of the first to fourth embodiments, the battery housing may have a horizontal portion perpendicular to the axial direction, and a plating layer may be formed on the horizontal portion.

[0023] According to a sixth embodiment, in any one of the first to fifth embodiments, at the maximum pressing depth of the lead, the step between the horizontal portion and the outer surface of the lead may be substantially non-existent.

[0024] According to the seventh embodiment, in any one of the first to sixth embodiments, a first inclined portion may be formed so that the inner diameter of the battery housing is widened in the axial outer direction, and is connected to the abutting portion.

[0025] According to the eighth embodiment, in the seventh embodiment, the height of the first inclined portion may be 0.3 mm or less.

[0026] According to the ninth embodiment, in any one of the seventh to eighth embodiments, the shape of the first inclined portion may be a flat inclined portion, a curved inclined portion, or a combination thereof.

[0027] According to the tenth embodiment, in any one of the seventh to ninth embodiments, the first inclined portion may be formed by a trimming process, a cutting process, or a combination thereof of the battery housing.

[0028] According to the eleventh embodiment, in any one of the first to tenth embodiments, the abutment portion may be formed by a cutting process, and the abutment portion may be in contact with the outer surface of the lead by 0.5 mm or more based on a cross-section parallel to the axial direction.

[0029] According to a twelfth embodiment, in any one of the first to eleventh 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.

[0030] In a 13th embodiment, a battery pack is provided including a battery cell of any one of the first to twelfth embodiments.

[0031] In a 14th embodiment, a vehicle including a battery pack according to the 13th embodiment is provided.

[0032]

[0033] 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.

[0034] 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.

[0035] 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.

[0036] 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.

[0037] 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.

[0038] 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.

[0039] Figure 1a schematically illustrates the appearance of a battery according to one embodiment of the present invention.

[0040] Figure 1b schematically illustrates the molding process of a conventional battery housing.

[0041] FIG. 1c schematically illustrates a can trimming process of a battery housing according to one embodiment of the present invention.

[0042] FIG. 1d schematically illustrates a cutting process of a battery housing according to one embodiment of the present invention.

[0043] Figure 1e illustrates a molding process of a battery housing according to one embodiment of the present invention.

[0044] Figure 2 schematically illustrates an exploded perspective view of an electrode assembly according to one embodiment of the present invention.

[0045] Figure 3 schematically illustrates a laminate of an electrode assembly according to one embodiment of the present invention.

[0046] 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.

[0047] 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.

[0048] 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.

[0049] 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.

[0050] Figure 8 schematically illustrates a process of storing an electrode assembly according to one embodiment of the present invention in a battery housing.

[0051] Figure 9 schematically illustrates a form in which a battery housing and a lead are combined according to one embodiment of the present invention.

[0052] Figure 10a is a schematic enlarged view of the area where a conventional battery housing and lead are connected.

[0053] FIG. 10b is a schematic enlarged view of a portion where a battery housing and a lead are combined according to one embodiment of the present invention.

[0054] FIG. 10c is a schematic enlarged view of a portion where a battery housing and a lead are joined according to another embodiment of the present invention.

[0055] FIG. 10d is a schematic enlarged view of a portion where a battery housing and a lead are joined according to another embodiment of the present invention.

[0056] Figure 11 schematically illustrates a battery pack according to one embodiment of the present invention.

[0057] Figure 12 schematically illustrates a vehicle according to one embodiment of the present invention.

[0058]

[0059] 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.

[0060] 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.

[0061] Justice

[0062] 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.

[0063] Throughout this specification, unless otherwise specifically stated, each component may be singular or plural.

[0064] 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.

[0065] 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.

[0066] 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.

[0067] 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.

[0068] 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.

[0069]

[0070] The present invention provides a battery (1).

[0071] 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.

[0072] 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.

[0073] 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.

[0074] 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.

[0075] 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.

[0076] 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.

[0077] 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.

[0078] 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.

[0079] Referring to FIG. 1a, 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).

[0080] In one embodiment of the present invention, 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 with a punch while holding it with a blank holder.

[0081] 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.

[0082] In one embodiment of the present invention, the metal sheet may have a plating layer formed on its surface, and for example, a plating layer including Ni may be formed.

[0083] In general, as shown in Fig. 1b, a die (D) is positioned on the outer surface of the battery housing (10), and a trimming punch (P11) for each molding is used to mold the inner surface of the battery housing, thereby forming a trimming portion (T) having a certain angle.

[0084] Thereafter, as shown in Fig. 1c, a die (D) is positioned on the outer surface of the battery housing (10), a step portion (not shown) perpendicular to the side wall portion (11) is formed on the inner surface, and then a trimming portion (T) is removed using a cutting means (not shown) provided in the punch (P2), thereby forming a first inclined portion (111) on the side wall portion.

[0085] Specifically, the first inclined portion (111) is formed on a part of the inner surface of the axially opposite end, and is formed so that the inner diameter of the battery housing (10) becomes wider as it goes outward in the axial direction.

[0086] Meanwhile, the height of the first inclined portion (111) formed on the conventional side wall portion, that is, the height of the first inclined portion (111) when viewed in the axial cross-section with reference to FIG. 1C, was approximately 0.7 mm. However, since the thickness of the lead (40), that is, the height of the outer circumferential surface of the lead (40), is only approximately 0.6 mm, when the lead is pressed into the battery housing, the first inclined portion is located at the part where the lead comes into contact with the battery housing. Accordingly, there was a problem that welding was difficult because the contact area between the lead and the battery housing was not sufficient.

[0087]

[0088] The present invention aims to solve the above-described problem by providing a shape of a battery housing (10) that can have sufficient contact with the outer surface of the lead (40).

[0089] In one embodiment of the present invention, the battery housing (10) may be formed by processing a conductive metal sheet through a deep drawing process as described above, and then cut by a cutting means (B) while supporting the inner surface of the side wall portion (11) with a jig (Z) as shown in Fig. 1d. The cutting means (B) may be a blade, a laser, or a combination thereof.

[0090] In addition, in one embodiment of the present invention, when the battery housing (10) is cut by a blade or laser, the battery housing (10) may have a horizontal portion (112) that is perpendicular to the side wall portion, and a side wall portion (11) that is parallel to the axial direction may be formed by being connected to the horizontal portion (112).

[0091] Alternatively, even when the battery housing (10) is cut by a blade or laser, the battery housing (10) may include a horizontal portion (112) and a first inclined portion (111) connected to the horizontal portion (112) and formed such that the inner diameter of the battery housing becomes wider as it goes outward in the axial direction.

[0092] At this time, the height of the first inclined portion (111) may have a very low height of 0.1 mm or less, more preferably 0.05 mm or less.

[0093] Meanwhile, in one embodiment of the present invention, a plating layer, for example, a plating layer including Ni, may be formed on the horizontal portion (112).

[0094] In another embodiment of the present invention, the battery housing (10) is formed by forming a conductive metal sheet through a deep drawing process as described above, and then, as shown in FIG. 1e, a die (D) is positioned on the outer surface of the battery housing (10), and each forming trimming punch (P12) is used to form the inner surface of the battery housing into a shape close to a right angle or a shape having a flat portion.

[0095] Thereafter, as shown in Fig. 1c, a die (D) is positioned on the outer surface of the battery housing (10), and a first inclined portion (111) can be formed on the side wall portion by removing the trimming portion (T) using a cutting means provided in the punch (P2).

[0096] Specifically, the first inclined portion (111) is formed on a portion of the inner surface of the axially opposite end, and may be formed so that the inner diameter of the battery housing (10) becomes wider as it goes outward in the axial direction. At this time, the height of the first inclined portion (111) may be 0.3 mm or less, preferably 0.2 mm or less or 0.1 mm or less.

[0097]

[0098] 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.

[0099] 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.

[0100] 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.

[0101]

[0102] 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.

[0103] 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.

[0104] 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.

[0105] 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.

[0106] 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.

[0107] 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.

[0108] 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).

[0109] In addition, the positive electrode active material layer may optionally further include a dispersant as needed.

[0110] 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.

[0111] 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.

[0112] 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.

[0113] 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.

[0114] 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.

[0115] 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.

[0116]

[0117] 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.

[0118] 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).

[0119] 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.

[0120] 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.

[0121] 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.

[0122] 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.

[0123]

[0124] 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.

[0125] 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.

[0126] 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.

[0127] 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.

[0128] In one embodiment of the present invention, the current collector (31) can be manufactured by punching, trimming, piercing, and bending a metal sheet.

[0129] 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).

[0130] 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).

[0131] 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).

[0132] 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).

[0133] 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.

[0134] 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.

[0135] In one embodiment of the present invention, the outer circumferential surface (41) of the lead is electrically connected to the mating portion (113) of the battery housing and sealedly fixed. 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).

[0136]

[0137] In one embodiment of the present invention, the lead (40) can be manufactured by pressing and forming a circular metal sheet.

[0138] Additionally, the lead (40) may have a substantially circular shape so as to seal the open end of the battery housing (10).

[0139] The outer circumferential surface (41) of the lead (40) may be formed to be substantially parallel to the axial direction, and more specifically, the outer circumferential surface (41) of the lead (40) may be formed to be substantially parallel to the side wall portion (11) of the battery housing (10).

[0140] Here, the expression “substantially” may mean allowing a difference within the error range of the measuring instrument when measuring the parallelism between the lead (40) and the side wall portion (11) based on a cross-section parallel to the axial direction.

[0141] In one embodiment of the present invention, the height of the outer peripheral surface (41) of the lead may be 0.5 mm to 0.8 mm, or more preferably 0.55 mm to 0.75 mm, based on a cross-section parallel to the axial direction. By satisfying the height of the outer peripheral surface (41) of the lead within the above range, the energy density of the battery is secured excellently, while the mechanical strength of the battery can be maintained, and the electrical resistance characteristics can also be excellent.

[0142]

[0143] The outer surface (41) of the above lead (40) and the mating portion (113) of the above battery housing (10) are joined to each other.

[0144] The structure of a conventional battery is as shown in Fig. 10a.

[0145] As described above, when a battery housing (10) is conventionally manufactured through a trimming process, a first inclined portion (111) is formed on the other end of the side wall portion so that the inner diameter of the battery housing becomes wider as it goes axially outward.

[0146] At this time, the height of the first inclined portion (111) is about 0.7 mm, and the height of the outer surface of the lead (40), that is, the thickness of the lead (40), is about 0.6 mm, so that the contact between the battery housing (10) and the lead (40) is not sufficient. Accordingly, even if the battery housing (10) and the lead (40) are welded, there is a problem in that the welding strength is not sufficiently secured. In addition, since the contact between the outer surface (41) of the lead (40) and the side wall portion (11) of the battery housing is insufficient, a difference may occur between the height of the outer surface of the lead (40) and the height of the horizontal portion (112) of the side wall portion (11).

[0147]

[0148] Meanwhile, FIGS. 10b, 10c and 10d are schematic enlarged views of the area where the battery housing and the lead are connected.

[0149] According to one aspect of the present invention, a battery (1) has a mating portion (113) formed on a part of the inner surface of the axial opposite end of the side wall portion (11), and the outer surface (41) of the lead (40) and the mating portion (113) are combined.

[0150] The above-mentioned mating portion (113) is a part of the inner surface of the side wall portion (11), and may be, for example, a part of the inner surface of the other axial end of the side wall portion.

[0151] In addition, when the first inclined portion (111) is formed, the abutting portion (113) may include a portion that is continuous with the first inclined portion (111), and when the first inclined portion (111) is not formed, it may include an inner surface that is connected to the horizontal portion (112).

[0152] In one embodiment of the present invention, the abutting portion (113) may contact the outer surface (41) of the lead (40) by 40% or more, preferably 50% or more or 60% or more, based on a cross-section parallel to the axial direction, of the height of the outer surface of the lead. When the above contact range is satisfied, the sealing property and mechanical strength of the battery can be further improved.

[0153] For example, when the height of the outer surface of the lead (41) is 0.6 mm, the contact length based on the cross-section parallel to the axial direction of the abutment portion (113) and the outer surface of the lead (41) may be 0.24 mm or more, preferably 0.3 mm or more or 0.36 mm or more.

[0154] In addition, in one embodiment of the present invention, the abutting portion (113) can contact the outer peripheral surface (41) of the lead by a length of 0.3 mm or more, preferably 0.35 mm or more or 0.4 mm or more, based on a cross-section parallel to the axial direction. Even in this case, by satisfying the above contact range, the sealing property and mechanical strength of the battery can be further improved.

[0155]

[0156] In one embodiment of the present invention, when the lead (40) is pressed in to the maximum, there may be no substantial step between the horizontal portion (112) and the outer surface of the lead (40). That is, when the lead (40) is pressed into the battery housing (10) and performs its function, the outer surface of the lead (40) and the abutting portion (113) of the battery housing (10) may be substantially horizontal.

[0157] For example, as shown in FIGS. 10b and 10c, when the outer surface (41) of the lead and the mating portion (113) of the battery housing (10) are sufficiently contacted and joined, the difference in height between the horizontal portion (112) from the electrode assembly (20) and the height of the outer surface of the lead (40) from the electrode assembly (20) when the lead (40) is pressed in to the maximum may be 30% or less, preferably 20% or less, 10% or less, or 5% or less, based on the height of the outer surface (41) of the lead.

[0158] At this time, the height can be measured based on the electrode assembly (20), for example, the notching tab (27) of the electrode assembly (20), and the height difference can be maintained in a state where there is substantially no difference.

[0159]

[0160] In one embodiment of the present invention, the first inclined portion (111) can be formed by a trimming process, a cutting process, or a combination thereof of the battery housing (10).

[0161] In addition, in one embodiment of the present invention, the battery (1) is connected to the mating portion (113) as illustrated in FIG. 10b, and a first inclined portion (111) may be formed so that the inner diameter of the battery housing (10) becomes wider as it goes axially outward. At this time, the outer peripheral surface (41) of the lead (40) may come into contact with the mating portion (113).

[0162] The battery housing (10) illustrated in FIG. 10b can be formed by forming a conductive metal sheet using a deep drawing process as illustrated in FIG. 1e, and then positioning a die (D) on the outer surface of the battery housing (10) and using each forming trimming punch (P12) to form the inner surface of the battery housing to have a shape close to a right angle or a flat portion.

[0163] Thereafter, a die (D) is positioned on the outer surface of the battery housing (10), and a first inclined portion (111) can be formed on the side wall by removing the trimming portion (T) using a cutting means provided in the punch (P2).

[0164] At this time, the height of the first inclined portion (111) may be 0.3 mm or less, preferably 0.25 mm or less, 0.2 mm or less, 0.15 mm or less, or 0.1 mm or less. When the height of the first inclined portion (111) is adjusted to satisfy the above range, the length of the abutting portion (113) increases, so that a sufficient area can come into contact with the outer surface (41) of the lead (40), and thereby the mechanical strength of the battery can be excellently secured.

[0165] In one embodiment of the present invention, the shape of the first inclined portion (111) may be a flat inclined portion, a curved inclined portion, or a combination thereof. For example, as illustrated in FIG. 1e, depending on the shape of each forming trimming punch (P12), the first inclined portion (111) may be formed as a flat inclined portion, a curved inclined portion with a curved surface, or a shape in which a flat inclined portion and a curved inclined portion are combined.

[0166] In one embodiment of the present invention, the shape of the first inclined portion (111) may be a curved inclined portion, as illustrated in Fig. 10c. At this time, the height of the first inclined portion (111) may be 0.2 mm or less, 0.15 mm or less, or 0.1 mm or less.

[0167] At this time, the point where the flat inclined portion or curved inclined portion of Fig. 10b or 10c ends is the first inclined portion (111), and a part of the side wall portion (11) that is connected to the first inclined portion (111) and is parallel to the axial direction can be formed as a butting portion (113).

[0168]

[0169] In another embodiment of the present invention, the battery housing (10) may not have the first inclined portion (111) formed according to the method of the cutting process as illustrated in FIG. 10d. In this case, the side wall portion (11) may be formed in a form in which the horizontal portion (112) and the abutting portion (113) are connected to each other.

[0170] The above-mentioned abutment portion (113) can be formed by a cutting process as illustrated in Fig. 10c, and can be in contact with the outer surface (41) of the lead (40) by 0.5 mm or more, preferably 0.6 mm or more, based on a cross-section parallel to the axial direction. That is, the abutment portion (113) can be formed in a form in which it is in contact with the outer surface (41) of the lead (40) over its entire area.

[0171] Meanwhile, even when the battery housing (10) is processed through a cutting process, a first inclined portion (111) can be formed. At this time, the height of the first inclined portion (111) can be formed to be 0.1 mm or less, more preferably 0.05 mm or less.

[0172]

[0173] In one embodiment of the present invention, the outer surface (41) of the lead and the mating portion (113) of the battery housing may be welded to form a welded portion. The welding may include laser welding, ultrasonic welding, CO2 welding, etc.

[0174] 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.

[0175]

[0176] 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.

[0177] That is, the lead (40) may include an outer surface (41), an electrode connection portion (42), a flat portion (43), a bridge (44), and a support surface (45) from the radially outer side.

[0178] In one embodiment of the present invention, the support surface (45) may be formed to extend horizontally inwardly in a radial direction. Since the outer surface of the support surface (45) has a flat plane shape, it can function as a foot of the battery when the battery is placed so that the lead (40) is placed on the floor.

[0179] 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.

[0180] 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.

[0181] 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).

[0182] 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).

[0183] 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.

[0184] 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.

[0185] 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).

[0186] 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.

[0187] 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).

[0188] 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).

[0189] 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.

[0190] 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.

[0191] 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.

[0192] In one embodiment of the present invention, the electrode connecting portions (42) may be provided in three pieces at intervals of 120°.

[0193] 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.

[0194] 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).

[0195] 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).

[0196] 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.

[0197] 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).

[0198] 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).

[0199] 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.

[0200]

[0201] 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).

[0202] 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.

[0203] In one embodiment of the present invention, the liquid injection port (46) may be closed by covering a plug (50) as illustrated in FIG. 9. The rim of the plug (50) may be sealed with the rim of the liquid injection port (46). The sealing may be achieved by seam welding or other known sealing methods.

[0204] 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.

[0205] 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.

[0206] 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.

[0207] 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).

[0208] 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.

[0209] 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.

[0210] 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).

[0211] 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.

[0212] 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).

[0213]

[0214] 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.

[0215] In one embodiment of the present invention, a support surface (45) extending radially flatly from the lead (40) is provided, the electrode connection portion (42) is 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).

[0216] 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.

[0217] 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 outer peripheral 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.

[0218] 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).

[0219] 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.

[0220] 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).

[0221] 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.

[0222] 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).

[0223]

[0224] 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).

[0225] 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.

[0226] 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.

[0227] 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).

[0228] 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.

[0229]

[0230] Referring to Fig. 11, 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.

[0231] 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.

[0232] 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. 12, the vehicle's mileage relative to its energy consumption can be further increased.

[0233] 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.

[0234]

[0235] 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.

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, 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 lid covering the open end and coupled with the battery housing, A mating portion is formed on a part of the inner surface of the axial end of the side wall portion, A battery characterized in that the outer surface of the lead and the mating portion are combined.

2. In claim 1, A battery characterized in that the above-mentioned mating portion is in contact with the outer surface of the lead by 40% or more based on a cross-section parallel to the axial direction and a height of 100% or more of the outer surface of the lead.

3. In claim 1, A battery characterized in that the above-mentioned mating portion contacts the outer surface of the lead for a length of 0.3 mm or more based on a cross-section parallel to the axial direction.

4. In claim 1, A battery characterized in that the height of the outer surface of the lead is 0.5 mm to 0.8 mm based on a cross-section parallel to the axial direction.

5. In claim 1, The above battery housing has a horizontal portion that is perpendicular to the axial direction, A battery characterized in that a plating layer is formed on the above horizontal portion.

6. In claim 5, At the maximum indentation depth of the above lead, A battery wherein the step between the horizontal portion and the outer surface of the lead is substantially non-existent.

7. In claim 1, It is connected to the above mating part, A battery characterized in that a first inclined portion is formed so that the inner diameter of the battery housing increases in the axial outward direction.

8. In claim 7, A battery characterized in that the height of the first inclined portion is 0.3 mm or less.

9. In claim 7, A battery characterized in that the shape of the first inclined portion is a flat inclined portion, a curved inclined portion, or a combination thereof.

10. In claim 7, A battery characterized in that the first inclined portion is formed by a trimming process, a cutting process, or a combination thereof of the battery housing.

11. In claim 1, The above mating portion is formed by a cutting process, A battery characterized in that the above-mentioned mating portion is in contact with the outer surface of the lead by 0.5 mm or more based on a cross-section parallel to the axial direction.

12. 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.

13. A battery pack comprising a battery cell according to any one of claims 1 to 12.

14. A vehicle comprising the battery pack of claim 13.

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