The battery, the battery pack including the battery, and the vehicle.

Abstract

A battery is provided, comprising: a battery casing including a sidewall portion, a bottom portion connected to one axial end of the sidewall portion, and an open end portion disposed at the other axial end portion of the sidewall portion; an electrode assembly in which a first electrode, a second electrode, and a diaphragm inserted therebetween are wound around a winding axis, wherein a tab of the second electrode is received inside the battery casing to face the open end portion; and a cap covering the open end portion of the battery casing and electrically connected to the second electrode. A first inclined portion is formed at the other axial end portion of the sidewall portion such that the inner diameter of the battery casing increases outward in the axial direction, and an abutment surface is formed on the outer peripheral surface of the cap such that the outer diameter of the cap increases outward in the axial direction, and at least a portion of the abutment surface contacts and engages with the first inclined portion.

Description

Technical Field

[0001] This disclosure relates to batteries, battery packs including such batteries, and vehicles.

[0002] This application claims priority to and is based on Korean Patent Application No. 10-2024-0091338 filed with the Korean Intellectual Property Office on July 10, 2024, and Korean Patent Application No. 10-2025-0087099 filed with the Korean Intellectual Property Office on June 30, 2025, the disclosures of which are incorporated herein by reference in their entirety. Background Technology

[0003] Secondary batteries, which offer high applicability across product categories and have electrical characteristics such as high energy density, are widely used not only in portable devices but also in electric vehicles (EVs) or hybrid electric vehicles (HEVs) powered by electric power sources.

[0004] Rechargeable batteries are gaining attention as a new energy source for enhancing environmental sustainability and energy efficiency, not only because of their major advantage of significantly reducing the use of fossil fuels, but also because they do not produce byproducts from energy use.

[0005] Currently widely used rechargeable batteries include lithium-ion batteries, lithium polymer batteries, nickel-cadmium batteries, nickel-metal hydride batteries, and nickel-zinc batteries. The operating voltage of a single rechargeable battery cell is approximately 2.5V to 4.5V.

[0006] Therefore, when a higher output voltage is required, a battery module or battery pack can be configured by connecting multiple battery cells in series. Alternatively, a battery module or battery pack can be configured by connecting multiple battery cells in parallel, depending on the required charge / discharge capacity. Thus, the number of battery cells included in a battery module or battery pack and their electrical connections can be configured in various ways according to at least one of the required output voltage and charge / discharge capacity.

[0007] Battery cells can be classified into cylindrical battery cells, prismatic battery cells, and pouch battery cells. In the case of cylindrical batteries, the positive electrode plate, the negative electrode plate, and the separator inserted therein as an insulator are wound together to form a wound electrode assembly, which is then inserted together with the electrolyte into the battery casing to form the battery.

[0008] As one implementation, one side of the cylindrical battery casing can be open, and the cover can be welded to that side. However, if sufficient contact area cannot be ensured between the battery casing and the cover, the weldability between them may deteriorate, leading to reduced weld strength or electrolyte leakage, which could increase product defects.

[0009] Recently, seam welding has been investigated as a method for connecting the cover and battery housing, replacing crimping and pressing methods. Seam welding is a process of welding the battery housing and the cover, specifically assembling them by joining the inner surface of the sidewall of the battery housing and the outer surface of the cover. To increase the strength of the seam weld, the contact area at the joint between the battery housing and the cover must be wide, and the gap between the cover and the battery housing must be minimized. Summary of the Invention

[0010] Technical issues

[0011] This disclosure was designed to address the problems in the related technologies, and therefore aims to provide a welding structure for a battery housing and a cover that maximizes the contact area between the battery housing and the cover, and a battery on which the welding structure is applied.

[0012] In addition, this disclosure aims to provide an interference fit structure having a novel shape that can increase the contact area between the battery casing and the cover and improve the welding strength, and a battery on which the interference fit structure is applied.

[0013] Additionally, this disclosure aims to provide a battery that allows the cover to function as a current collector, thereby removing the current collector from the junction between the electrode assembly, the battery housing, and the electrode terminals and ensuring a reliable electrical connection.

[0014] In addition, this disclosure aims to provide an economical battery that simplifies the manufacturing process and reduces manufacturing costs by eliminating current collectors.

[0015] Furthermore, this disclosure aims to provide a cylindrical battery capable of reducing product defects caused by reduced welding strength or electrolyte leakage, as well as a battery pack and a vehicle including the battery.

[0016] The technical problems that this disclosure seeks to solve are not limited to those described above, and those skilled in the art will clearly understand from the description of the invention below that other problems not mentioned above will also be apparent.

[0017] Technical solution

[0018] According to one aspect of this disclosure, a battery as described in the following embodiments, a battery pack including the battery, and a vehicle are provided.

[0019] According to a first implementation, a battery is provided, comprising: a battery housing having a sidewall, a bottom connected to one axial end of the sidewall, and an open end disposed at another axial end of the sidewall; an electrode assembly having a first electrode, a second electrode, and a diaphragm inserted between the first electrode and the second electrode, the first electrode, the second electrode, and the diaphragm being wound around a winding axis and housed inside the battery housing such that the tab of the second electrode faces the open end; and a cover configured to cover the open end of the battery housing and electrically connected to the second electrode, wherein a first inclined portion is formed at the other axial end of the sidewall such that the inner diameter of the battery housing increases in an axially outward direction, wherein an abutment surface is formed on the outer peripheral surface of the cover such that the outer diameter of the cover increases in an axially outward direction, and wherein at least a portion of the abutment surface contacts and is connected to the first inclined portion.

[0020] According to the second implementation, in the first implementation, the abutting surface of the cover and the first inclined portion of the battery casing can fit together without gaps.

[0021] According to the third implementation, in one of the first and second implementations, when viewed in a cross section parallel to the axial direction, the inclination of the abutment surface and the inclination of the first inclined portion can be substantially the same.

[0022] According to the fourth implementation, in one of the first to third implementations, when viewed in a cross section parallel to the axial direction, the abutting surface may have an inclination of 1° to 45° relative to the axial direction.

[0023] According to the fifth implementation, in one of the first to fourth implementations, the abutting surface of the cover and the first inclined portion of the battery casing can be welded to form a welded portion.

[0024] According to the sixth implementation, in the fifth implementation, based on 100% of the area of ​​the first inclined portion, the welded portion can be formed to cover 90% to 100% of the area of ​​the first inclined portion.

[0025] According to the seventh implementation, in one of the first to sixth implementations, the abutting surface of the cover may include an inclined abutting surface and a vertical abutting surface.

[0026] According to the eighth implementation, in one of the first to seventh implementations, the battery housing may include a horizontal portion connected to the first inclined portion and perpendicular to the axial direction, and the horizontal portion may substantially not have a step at the portion of its contact cover outer surface.

[0027] According to the ninth implementation, in one of the first to eighth implementations, the first inclined portion can be formed by a trimming process for the battery casing.

[0028] According to the tenth implementation, in one of the first to ninth implementations, the cover may include an electrode connection portion electrically connected to the tab of the second electrode.

[0029] According to the eleventh implementation, in the tenth implementation, the electrode connection portion can be located at a position recessed from the radially inner side of the abutment surface toward the axially inner side.

[0030] According to the twelfth implementation, in one of the tenth to eleventh implementations, the electrode connection portions can be arranged at equal intervals in the circumferential direction.

[0031] According to the thirteenth implementation, in one of the first to twelfth implementations, the cover may include an exhaust portion.

[0032] According to the fourteenth implementation, in one of the first to thirteenth implementations, an injection hole can be provided at the center of the cover.

[0033] According to the fifteenth implementation, in one of the first to fourteenth implementations, the bottom of the battery casing may have a first electrode terminal that is configured to be 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.

[0034] According to the sixteenth implementation, a battery pack is provided that includes a battery according to one of the first to fifteenth implementations.

[0035] According to the seventeenth implementation, a vehicle including a battery pack according to the sixteenth implementation is provided.

[0036] Beneficial effects

[0037] According to one aspect of this disclosure, the battery can maximize the contact area between the battery casing and the cover, thereby improving welding strength and enhancing product durability and reliability.

[0038] In addition, according to one aspect of this disclosure, the battery can increase the contact area and effectively ensure the welding strength by using a novel interference fit structure between the battery casing and the cover.

[0039] Additionally, according to one aspect of this disclosure, a battery can ensure a reliable electrical connection between the electrode assembly and the battery housing by allowing the cover to be used as a current collector, thereby eliminating the need for a separate current collector.

[0040] Therefore, the battery according to one aspect of this disclosure can simplify the structure, streamline the manufacturing process, and reduce manufacturing costs by eliminating the current collector.

[0041] In addition, the battery according to one aspect of this disclosure can reduce product defects caused by reduced welding strength or electrolyte leakage, thereby improving overall product quality.

[0042] Furthermore, based on the aforementioned effects, the battery according to one aspect of this disclosure can not only enhance the quality and safety of cylindrical batteries, but also enhance the quality and safety of battery packs and vehicles including the battery.

[0043] However, the effects that can be obtained from this disclosure are not limited to those described above, and those skilled in the art will clearly understand from the following description of the invention that are not mentioned above. Attached Figure Description

[0044] The accompanying drawings illustrate preferred embodiments of the present disclosure and, together with the foregoing disclosure, serve to provide a further understanding of the technical features of the present disclosure; therefore, the present disclosure is not to be construed as limited to the drawings.

[0045] Figure 1a The appearance of a battery according to an embodiment of the present disclosure is illustrated schematically.

[0046] Figure 1b The process of using a mold and a punch to trim the open end of a battery casing to form a first inclined portion is illustrated schematically.

[0047] Figure 2 This is an exploded perspective view schematically illustrating an electrode assembly according to an embodiment of the present disclosure.

[0048] Figure 3 A laminate of an electrode assembly according to an embodiment of the present disclosure is illustrated schematically.

[0049] Figure 4 An electrode assembly manufactured by winding the laminate of the electrode assembly into a core shape, according to an embodiment of the present disclosure, is illustrated schematically.

[0050] Figure 5 An electrode assembly manufactured by winding the laminate of the electrode assembly into a core shape, according to an embodiment of the present disclosure, is illustrated schematically.

[0051] Figure 6 A core-shaped electrode assembly according to an embodiment of the present disclosure is schematically illustrated, the core-shaped electrode assembly having a side with a current collector attached and a side without a current collector attached.

[0052] Figure 7A core-shaped electrode assembly according to an embodiment of the present disclosure is schematically illustrated, the core-shaped electrode assembly having a side with a current collector attached and a side without a current collector attached.

[0053] Figure 8 The process of inserting an electrode assembly into a battery casing according to an embodiment of the present disclosure is illustrated schematically.

[0054] Figure 9 A cover connected to a battery housing according to an embodiment of the present disclosure is illustrated schematically.

[0055] Figure 10a This is an enlarged view schematically illustrating the joint between the cover and the battery housing according to an embodiment of the present disclosure.

[0056] Figure 10b This is an enlarged view schematically illustrating the joint between the cover and the battery housing according to another embodiment of the present disclosure.

[0057] Figure 11 A cap connected to a cover is illustrated schematically according to an embodiment of the present disclosure.

[0058] Figure 12 A battery pack according to an embodiment of the present disclosure is illustrated schematically.

[0059] Figure 13 A vehicle according to an embodiment of the present disclosure is illustrated schematically. Detailed Implementation

[0060] It should be understood that the terms used in the specification and appended claims should not be construed as limited to their general or dictionary meanings, but rather as being interpreted based on their meanings and concepts corresponding to the technical aspects of this disclosure, on the basis of the principle that the inventors are allowed to define the terms appropriately for the best interpretation.

[0061] The terminology used herein is intended to describe exemplary embodiments only and is not intended to limit this disclosure. Unless the context clearly indicates otherwise, the singular forms used herein are also intended to include the plural forms.

[0062] <Definition>

[0063] Throughout this specification, unless otherwise stated, the statement “an element includes another component” should be interpreted as indicating that the element may also include other components, rather than excluding other components.

[0064] Throughout this specification, unless otherwise stated, the corresponding elements may include one or more elements.

[0065] Throughout the specification, the configuration of an element being positioned "in the upper (or lower) part" or "at the top (or bottom)" of the target element indicates that the element can be configured to contact the upper (or lower) surface of the target element, and that another element can be inserted between the target element and the element positioned at the top (or bottom) of the target element.

[0066] Throughout the specification, the phrase “an element is ‘connected,’ ‘joined,’ or ‘joined’ to another element” should be understood to mean that two elements can be directly connected or joined to each other, and that another element can be “inserted” between the two elements, or that two elements can be “connected,” “joined,” or “joined” via another element.

[0067] Throughout this specification, unless otherwise stated, the expression "A and / or B" may refer to A, B, or both A and B, and the expression "C to D" may refer to a range of values ​​that are equal to or greater than C and equal to or less than D.

[0068] Throughout this specification, the axial direction refers to the direction in which the winding axis of the electrode assembly wound in a core shape extends, the radial direction refers to the direction of movement toward or away from the winding axis, and the circumferential direction refers to the direction around the axis.

[0069] The embodiments described in this specification and the configurations illustrated in the accompanying drawings are merely preferred examples of this disclosure and do not represent the full range of technical concepts of this disclosure. Therefore, it should be understood that various equivalents and modifications that can replace them at the time of filing the application are possible.

[0070] This disclosure provides for battery 1.

[0071] The battery disclosed herein may, for example, have a shape factor ratio greater than about 0.4 (defined as the diameter of a cylindrical battery). The ratio of the diameter of the cylindrical battery to its height (H), which is a value obtained by dividing the diameter of the cylindrical battery by its height.

[0072] Here, the form factor refers to the value indicating the diameter and height of a cylindrical battery. Cylindrical batteries suitable for pressure testing instruments can be, for example, 46110, 48750, 48110, 48800, or 46800 cells. In the form factor value, the first two digits indicate the cell diameter, the next two digits indicate the cell height, and the final digit "0" indicates that the cell has a circular cross-section.

[0073] The battery to be used in the pressure tester can be a roughly cylindrical battery with a diameter of about 46 mm, a height of about 110 mm, and a form factor ratio of 0.418.

[0074] According to another embodiment, the battery can be a generally cylindrical battery having a diameter of about 48 mm, a height of about 75 mm, and a form factor ratio of 0.640.

[0075] According to another embodiment, the battery can be a generally cylindrical battery having a diameter of about 48 mm, a height of about 110 mm, and a form factor ratio of 0.418.

[0076] According to another embodiment, the battery can be a generally cylindrical battery having a diameter of about 48 mm, a height of about 80 mm, and a form factor ratio of 0.600.

[0077] According to another embodiment, the battery can be a generally cylindrical battery having a diameter of about 46 mm, a height of about 80 mm, and a form factor ratio of 0.575.

[0078] The pressure tester disclosed herein can also be applied to battery cells with a form factor ratio of about 0.4 or less, such as 18650 cells and 21700 cells. The 18650 cell has a diameter of about 18 mm, a height of about 65 mm, and a form factor ratio of 0.277. The 21700 cell has a diameter of about 21 mm, a height of about 70 mm, and a form factor ratio of 0.300.

[0079] Referring to FIG1, the battery housing 10 of this disclosure includes a cylindrical sidewall 11, a bottom 12 connected to one axial end of the sidewall 11, and an open end disposed at the other axial end of the sidewall 11.

[0080] The bottom 12 and the sidewall 11 can be manufactured by forming a conductive metal sheet using a deep drawing process, and then trimming the ends of the sidewall 11 with a punch while the sidewall 11 is held in a blank holder.

[0081] Specifically, the battery casing 10 can be formed by deep drawing a steel plate to have a cylindrical body and a trimmed portion that extends to be radially outward in an axial outward direction.

[0082] Subsequently, as Figure 1b As shown, the can trimming process can be performed by placing a mold D on the outer surface of the battery housing and cutting the battery housing with a punch P. Specifically, the mold D can be positioned on the outer surface of the battery housing 10, and a stepped portion (not shown) perpendicular to the side wall 11 of the battery housing can be formed on the inner surface of the battery housing. The trimmed portion can then be cut and removed by a cutting device (not shown) provided in the punch P, thereby forming a first inclined portion 111 on the inner surface of the battery housing. In this way, the first inclined portion 111 is formed at another axial end such that the inner diameter of the battery housing 10 increases in the axially outward direction.

[0083] In embodiments of this disclosure, the conductive metal sheet may include, but is not limited to, aluminum, steel, stainless steel, etc.

[0084] In embodiments of this disclosure, the first inclined portion 111 may have a chamfered shape or may be rounded.

[0085] In embodiments of this disclosure, the electrode assembly 20 is housed inside the battery casing 10. The electrode assembly 20 is manufactured in the following manner: Figure 2 The fabrication process illustrates the preparation of a first electrode 21, a second electrode 22, and a diaphragm 28, each having a predetermined width and extending in the longitudinal direction. Figure 3 The first electrode 21, the diaphragm 28, the second electrode 22 and the diaphragm 28 are stacked in sequence to form a laminate, and the laminate is wound around the winding axis into a core shape.

[0086] In embodiments of this disclosure, the first electrode 21 can be a positive electrode, and the second electrode 22 can be a negative electrode, and vice versa.

[0087] In embodiments of this disclosure, the first electrode 21 and the second electrode 22 are manufactured in the form of sheets. The electrode sheets may be manufactured in the form of an active material layer 24 coated on the surface of a metal foil 23. The electrode sheets may include a coated portion 25 with the active material layer 24 and an uncoated portion 26 without the active material layer 24. The positive electrode may have an uncoated portion 26 on one width direction side, and the negative electrode may have an uncoated portion 26 on the other width direction side.

[0088] In embodiments of this disclosure, a positive electrode can be manufactured by coating a positive electrode current collector with a positive electrode forming composition comprising a positive electrode active material, a binder, a conductive material, and a solvent.

[0089] In embodiments of this disclosure, the positive electrode active material can be any positive electrode active material used in the positive electrode of a conventional electrochemical device. For example, the positive electrode active material can be a lithium composite oxide of lithium manganese oxide, lithium cobalt oxide, lithium nickel oxide, lithium iron oxide, or combinations thereof.

[0090] In this case, the positive electrode active material can be present in an amount of 80 wt% to 99 wt%, preferably 85 wt% to 98 wt%, relative to the total solids content of the positive electrode forming composition. If the content of the positive electrode active material meets the above range, excellent capacity properties can be provided.

[0091] There are no particular restrictions on the positive electrode current collector, as long as it is conductive and does not cause chemical changes in the battery. The positive electrode current collector can be, for example, stainless steel, aluminum, nickel, titanium, calcined carbon, or aluminum or stainless steel with surface treatments using carbon, nickel, titanium, silver, etc.

[0092] Adhesives are components that facilitate the bonding of active and conductive materials, as well as the bonding with current collectors, and are typically added in amounts from 1 wt% to 30 wt% relative to the total solid weight of the cathode-forming composition. Examples of such adhesives 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, and various copolymers.

[0093] The conductive material can typically be added in amounts ranging from 1 wt% to 30 wt% relative to the total solid weight of the positive electrode forming composition.

[0094] There are no particular restrictions on conductive materials, as long as they are conductive and do not cause chemical changes in the battery. Examples of conductive materials can 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; fluorinated carbon; metal powders such as aluminum and nickel powder; conductive whiskers such as zinc oxide and potassium titanate; conductive metal oxides such as titanium oxide; and polyphenylene derivatives. Specific examples of commercially available conductive materials include acetylene black (purchased from Chevron Chemicals), electrochemical black (purchased from Electrochemical Singapore Pte Ltd), conductive products (purchased from Gulf Oil), Ketjen black, EC series (purchased from Armak), Vulcan XC-72 (purchased from Cabot Corporation), and Super P (purchased from TMICOR).

[0095] In addition, the positive electrode active material layer may optionally include a dispersant as needed.

[0096] Any material can be used as a positive electrode dispersant without particular limitation. For example, aqueous or organic dispersants can be used selectively as needed. Preferably, the dispersant can be at least one of the following: cellulose-based compounds, polyepoxides, polyvinyl alcohol, polyvinylpyrrolidone, polyvinyl acetal, polyvinyl ether, polyvinyl sulfonic acid, polyvinyl chloride (PVC), polyvinylidene fluoride, chitosan compounds, starch, linear starch, polyacrylamide, poly-N-isopropylacrylamide, poly-N,N-dimethylacrylamide, polyethyleneimine, polyoxyethylene, poly(2-methoxyethoxyethylene), poly(acrylamide-co-diallyldimethylammonium chloride), acrylonitrile-butadiene-styrene (ABS) polymers, a mixture of acrylonitrile / styrene / acrylate (ASA) polymers and propylene carbonate, styrene-acrylonitrile (SAN) copolymers, methyl methacrylate-acrylonitrile-butadiene-styrene (MABS) polymers, styrene-butadiene rubber, nitrile rubber, and fluororubber or mixtures thereof. Therefore, hydrogenated nitrile rubber (H-NBR) can be used. When the positive electrode active material layer also includes a dispersant, the dispersibility of the components (especially conductive materials) of the positive electrode active material layer can be increased, but it is not limited to this.

[0097] Alternatively, the solvent can be a solvent commonly used in the art, such as dimethyl sulfoxide (DMSO), isopropanol, N-methylpyrrolidone (NMP), acetone, or water, and any of these can be used alone or in mixtures of two or more. Considering the coating thickness and manufacturing yield of the slurry, the amount of solvent used is sufficient to dissolve or disperse the positive electrode active material, conductive material, and binder, and has a viscosity that allows for excellent thickness uniformity during subsequent coating processes used to manufacture the positive electrode.

[0098] The negative electrode according to this disclosure can be manufactured by coating a negative electrode current collector with a negative electrode forming composition comprising the aforementioned negative electrode active material, binder, conductive material, and solvent. Additionally, the negative electrode forming composition may optionally further comprise a dispersant as needed.

[0099] The negative electrode active material can be a compound capable of reversible lithium insertion and extraction. Preferably, the negative electrode may also include: a silicon-based negative electrode active material exhibiting high capacity; a carbon-based negative electrode active material; or a material such as Li... x Fe2O3 (0≤x≤1), Li x WO2 (0≤x≤1) and Sn x Me 1-x Me' y O zA metal composite oxide of (Me: Mn, Fe, Pb or Ge; Me': Al, B, P, Si, elements of Groups 1, 2 and 3 of the periodic table or a halogen; 0 < x ≤ 1; 1 ≤ y ≤ 3; and 1 ≤ z ≤ 8); lithium metal; a lithium alloy; a tin-based alloy; metal oxides such as SnO, SnO2, PbO, PbO2, Pb2O3, Pb3O4, Sb2O3, Sb2O4, Sb2O5, GeO, GeO2, Bi2O3, Bi2O4 and Bi2O5; a conductive polymer such as polyacetylene; a Li-Co-Ni-based material; titanium oxide; and a lithium titanium oxide. The silicon-based negative electrode active material may include at least one selected from the group consisting of: Si, SiOx (0.1 < x < 5), a Si-metal alloy, silicon oxide particles (SiOx) (0.1 < x < 5) doped or chemically bonded with a metal such as Mg, and an alloy of Si and SiOx (0.1 < x < 5). The carbon-based negative electrode active material may include at least one selected from the group consisting of: natural graphite, artificial graphite, amorphous hard carbon, low-crystalline soft carbon, carbon black, acetylene black, Ketjen black, Super P, graphene and fibrous carbon.

[0100] Any material having high conductivity and not causing chemical changes in the battery can be used for the negative electrode current collector without particular limitation. For example, copper, stainless steel, aluminum, nickel, titanium, calcined carbon, copper or stainless steel surface-treated with carbon, nickel, titanium or silver, and an aluminum-cadmium alloy can be used. Additionally, the negative electrode current collector generally has a thickness of 3 μm to 500 μm, and similar to the positive electrode current collector, the surface of the current collector can be finely textured to enhance the bonding strength of the negative electrode active material. For example, the negative electrode current collector can be used in various forms such as a film, sheet, foil, mesh, porous body, foam and nonwoven fabric.

[0101] Any material commonly used in electrode-forming compositions can be applied to the conductive material, binder, solvent or dispersant included in the negative electrode-forming composition without particular limitation. For example, the conductive material, binder, solvent or dispersant for the positive electrode-forming composition described above can be used in the negative electrode-forming composition.

[0102] In an embodiment of the present disclosure, the uncoated portion 26 can be exposed or protruded from the laminate in the width direction as Figure 2 and Figure 3 shown. The uncoated portion 26 itself can be used as an electrode tab.

[0103] In an embodiment of the present disclosure, the uncoated portion 26 can be slotted at a predetermined interval to form a flag-shaped slotted tab 27.

[0104] In an embodiment of the present disclosure, the slotted tab 27 can be as Figure 2 and Figure 3The shape shown is an isosceles trapezoid. Alternatively, the slotted tab 27 may have a semi-circular, semi-elliptical, triangular, rectangular, or parallelogram shape.

[0105] In embodiments of this disclosure, the slotted tabs 27 can be arranged along the longitudinal direction and can have the same width. However, the width of the slotted tabs can also gradually or progressively increase from the winding core toward the outer periphery.

[0106] In embodiments of this disclosure, the height of the slotted tab 27 can gradually increase from the winding core in the radially outward direction. However, the height of the slotted tab 27 can also be constant or gradually decrease.

[0107] In embodiments of this disclosure, the slotted tab 27 may be omitted from predetermined sections at the radial inner end and radial outer end of the uncoated portion 26. However, it should be understood that the slotted tab may not be omitted from the radial inner end of the uncoated portion, nor may it be omitted from the radial outer end of the uncoated portion.

[0108] In embodiments of this disclosure, in the core-shaped electrode assembly 20, the slotted tab 27 can be radially bent and flattened. The slotted tab 27 can be bent radially inward or outward. For example, as Figure 4 and Figure 5 As shown, the slotted tab 27 can be bent radially inward.

[0109] In embodiments of this disclosure, the slotted tab 27 can be bent individually during the process of winding the laminate to form the core-shaped electrode assembly 20. Alternatively, the slotted tab 27 can be bent simultaneously after the laminate is wound to form the core-shaped electrode assembly.

[0110] In embodiments of this disclosure, the slotted tabs 27 of the first electrode 21 and the slotted tabs 27 of the second electrode 22, which are bent in the radial direction to overlap each other, can be as follows: Figure 5 As shown, planes substantially perpendicular to the axial direction are provided at the two axial ends of the electrode assembly 20.

[0111] In embodiments of this disclosure, such as Figure 6 As shown, the current collector 31 can be coupled to a substantially flat surface provided by bending the slotted tabs 27 exposed at the two axial ends of the electrode assembly 20.

[0112] In embodiments of this disclosure, the current collector 31 can be manufactured by stamping, trimming, piercing, and bending metal sheets.

[0113] In embodiments of this disclosure, reference is made to Figure 6The current collector 31 may include: a terminal connection portion 32 extending radially from the center; an annular portion 33 connecting the distal edge of the terminal connection portion 32 in the circumferential direction; and an electrode connection portion 34 extending from the annular portion 33 toward the center but not connected to the terminal connection portion 32. The central portion of the terminal connection portion 32 may cover at least a portion of the central winding hole of the electrode assembly 20.

[0114] In embodiments of this disclosure, before the electrode assembly 20 is inserted into the battery housing 10, the electrode connection portion 34 can be joined to the slotted tab 27 of the first electrode 21 of the electrode assembly 20 by means of laser welding or the like.

[0115] In embodiments of this disclosure, reference is made to Figure 7 The current collector may not be connected to the slotted tab 27 of the second electrode 22 of the electrode assembly 20. This disclosure is not limited to a structure in which the current collector is not connected to the slotted tab 27 of the second electrode 22.

[0116] In embodiments of this disclosure, such as Figure 8 and Figure 9 As shown, the electrode assembly 20 can be housed within the battery housing 10 while the current collector 31 is aligned to face the bottom 12 of the battery housing 10. In this case, the insulator 16 can be inserted between the current collector 31 and the bottom 12 of the battery housing 10 to electrically insulate the current collector 31 and the bottom 12 from each other.

[0117] In embodiments of this disclosure, the terminal connection portion 32 of the current collector 31 can be joined to the first electrode terminal 13 fixed to the battery housing 10 by resistance welding, ultrasonic welding, or laser welding. A welding apparatus for welding the current collector 31 and the first electrode terminal 13 to form a weld can approach the rear surface of the center of the terminal connection portion 32 of the current collector 31 from another axial end of the electrode assembly 20 through a central winding hole in the electrode assembly 20, thereby performing the welding. Alternatively, the current collector 31 and the first electrode terminal 13 can also be joined using other methods such as brazing or soldering. That is, any method for electrically connecting and fixing the current collector 31 and the first electrode terminal 13 to each other can be applicable.

[0118] With the electrode assembly 20 housed within the battery casing 10 and the first electrode 21 connected to the first electrode terminal 13, the slotted tab 27 of the second electrode 22 can be directly connected to the cover 40, which is press-fitted through the open end of the battery casing 10. Therefore, the second electrode 22 is electrically connected to the cover 40 via the welded portion of the slotted tab 27. In addition to welding, other joining methods such as brazing or soldering can also be applied to the slotted tab 27 and the cover 40.

[0119] In embodiments of this disclosure, the abutting surface 41 of the cover is electrically connected to the sidewall 11 of the battery housing, thereby sealing and securing it. Therefore, the second electrode 22 can be electrically connected to the cover 40 and the battery housing 10. Various methods such as welding, brazing, and soldering, which allow for electrical connection and sealing, can be used to form the joint M between the cover 40 and the battery housing 10.

[0120] In embodiments of this disclosure, the cover 40 can be manufactured by pressing and forming a circular metal sheet.

[0121] Additionally, the cover 40 may have a generally disc-shaped shape to seal the open end of the battery casing 10.

[0122] As described above, when the battery casing 10 is manufactured using a finishing process, a first inclined portion 111 is formed at the other end of the sidewall, causing the inner diameter of the battery casing to increase in the axial outward direction. In this case, if the contact area between the cover 40 and the battery casing is insufficient, even if the battery casing 10 and the cover 40 are welded, the weld strength may be low, leading to electrolyte leakage and deterioration of mechanical strength. Therefore, even if the first inclined portion 111 is formed on the other end of the sidewall 11, a connection structure that ensures sufficient contact area with the cover 40 and a battery including the cover 40 are required.

[0123] An abutment surface 41 is formed on the outer peripheral surface of the cover 40 such that the outer diameter or radial circumference of the cover 40 increases in the axial outward direction. At least a portion of the abutment surface 41 contacts and engages with the first inclined portion 111 of the battery housing.

[0124] Reference Figure 10a The connection between the battery housing 10 and the cover 40 is described. The abutting surface 41 of the cover and the first inclined portion 111 of the battery housing can fit together without gaps. Even when the battery housing 10 and the cover 40 are joined, the appearance of the battery housing 10 or the cover 40 may remain unchanged.

[0125] In embodiments of this disclosure, there may be substantially no gap between the first inclined portion 111 of the battery housing and the cover 40. In this case, the term "substantially no gap" may refer to a situation where the gap measured between the cover 40 and the sidewall 11 falls within the tolerance range of the measuring instrument. For example, the gap between the abutting 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%, or less than 1% of the thickness of the first inclined portion 111, or the abutting surface 41 and the first inclined portion 111 may be in complete contact.

[0126] In embodiments of this disclosure, when viewed in a cross-section parallel to the axial direction, the inclination of the abutment surface 41 and the inclination of the first inclined portion 111 can be substantially the same. In this case, the term "substantially the same" can refer to the condition that when the angle formed with the axial direction is measured based on a cross-section parallel to the axial direction of the cover 40 and the sidewall 11, the obtained value is less than the error of the measuring instrument. For example, as... Figure 10a As shown, the abutment surface 41 and the first inclined portion 111 can each form an angle θ relative to the axial direction, and the angles θ can be substantially the same. In this case, the contact area between the abutment surface 41 and the first inclined portion 111 can be wider.

[0127] In embodiments of this disclosure, when viewed in a cross-section parallel to the axial direction, the abutment surface can have an inclination of 1° to 45° relative to the axial direction. That is, the angle θ between the abutment surface 41 and the first inclined portion 111 relative to the axial direction can fall within the range of 1° to 45°. In this case, the cover 40 can be stably mounted on the battery casing 10 to cover the open end, thereby further improving the electrolyte sealing performance.

[0128] In another embodiment of this disclosure, the abutting surface 41 of the cover is as follows: Figure 10b The device may include an inclined abutment surface 411 connected to the outer surface of the cover 40, and a vertical abutment surface 412 connecting the inclined abutment surface 411 and the inner surface of the cover 40.

[0129] In this case, the inclined abutment surface 411 can contact and connect to the first inclined portion 111, and the vertical abutment surface 412 can contact the inner surface of the sidewall 11 that is connected to the first inclined portion 111.

[0130] As described above, since the cover 40 includes an inclined abutment surface 411 and a vertical abutment surface 412, the cover 40 can be complementaryly connected to the sidewall 11, thereby improving the sealing performance of the battery. In addition, since the cover 40 and the battery housing 10 are stably connected at a specific location, the press-fit depth of the cover 40 can be maintained more consistently.

[0131] In embodiments of this disclosure, the abutting surface 41 of the cover and the first inclined portion 111 of the battery casing can be welded to form a welded portion. Welding may include laser welding, ultrasonic welding, CO2 welding, etc.

[0132] In embodiments of this disclosure, the weld portion can be formed to cover 90% to 100% of the area of ​​the first inclined portion 111, based on 100% of the area of ​​the first inclined portion 111. The surface area of ​​the abutment surface 41 can be larger than the surface area of ​​the first inclined portion 111, and a joint can be performed such that the abutment surface 41 covers most of the surface area of ​​the first inclined portion 111.

[0133] In embodiments of this disclosure, the battery housing 10 may include a horizontal portion 112 connected to the first inclined portion 111 and perpendicular to the axial direction. The horizontal portion 112 may be substantially without steps at the portion where it contacts the outer surface of the cover 40. That is, the horizontal portion 112 and the outer surface of the cover 40 may have the same height from the slotted tab 27 of the electrode assembly 20. In this case, with the other end of the battery serving as the bottom surface of the battery pack, the contact area with the battery pack housing can be increased, thereby improving heat exchange, etc.

[0134] In embodiments of this disclosure, such as Figure 9 As shown, the cover 40 may have an asymmetrical cross section parallel to the axial direction relative to the radially inner center.

[0135] In other words, the cover 40 may sequentially include an abutment surface 41, an electrode connection portion 42, a flat portion 43, a bridge 44, and a support surface 45 in the radial direction from the outside.

[0136] In embodiments of this disclosure, the support surface 45 extends horizontally from the abutment surface 41 in a radially inward direction. The outer surface of the support surface 45 is flat, so that when the battery is placed such that the cover 40 faces the ground, the support surface 45 can serve as a foot for the battery.

[0137] In embodiments of this disclosure, 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 slotted tab 27 of the electrode assembly.

[0138] In embodiments of this disclosure, the electrode connection portion 42 may be disposed on the cover 40 radially inside the support surface 45 so as to extend horizontally in the radial direction. (See also...) Figure 9 The electrode connection part 42 can be located in an axially recessed position.

[0139] In embodiments of this disclosure, the press-fit depth from the cover 40 to the battery housing 10 can be determined by the connection between the electrode connection portion 42 of the cover 40 and the tab of the second electrode 22 of the electrode assembly 20 housed in the battery housing 10. That is, the bottom surface of the electrode connection portion 42 can be configured to be closest to the electrode assembly 20 on the bottom surface of the cover 40. In this case, when the electrode connection portion 42 is connected to the electrode assembly 20, the remaining portion of the cover 40, excluding the electrode connection portion 42, can be spaced apart from the electrode assembly 20.

[0140] In embodiments of this disclosure, 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 together. They can be joined by welding. Figure 9 As shown, the weld between the electrode connection portion 42 and the slotted tab 27 of the second electrode 22 can be formed by irradiating the axial outer surface of the electrode connection portion 42 with a laser beam in the axial direction from the outside. The laser beam can be irradiated in a scanning manner along the radial direction to form a weld portion W extending in the radial direction. The electrode connection portion 42 can be connected to the electrode assembly 20 face-to-face. The electrode connection portion 42 can be connected to the metal foil 23.

[0141] As described above, the cover 40 serves as a cap to close the open end of the battery housing 10, and also as a current collector for the second electrode 22. Therefore, the cover 40 can have a second polarity, and the sidewall 11 welded to the cover 40 and the bottom 12 connected to the cover 40 can also have a second polarity.

[0142] In embodiments of this disclosure, the electrode connection portion 42 may extend radially outward by half or more of the radius of the battery housing 10. Preferably, the electrode connection portion 42 may extend at least 0.7 times the radius of the battery housing 10. The electrode connection portion 42 may extend radially in a flat shape.

[0143] In embodiments of this disclosure, the electrode connection portion 42 may occupy at least 50% of the total area of ​​the battery casing 10.

[0144] In embodiments of this disclosure, the electrode connection portion 42 of the cover 40 may have a bottom surface extending in a flat shape with sufficient width, thereby ensuring a sufficient welding area with the tab of the second electrode 22.

[0145] In embodiments of this disclosure, the current collector can be electrically bonded to the tab of the second electrode 22, and the electrode connection portion 42 can be bonded to the current collector for electrical connection to the tab of the second electrode 22. That is, the current collector can be soldered to the tab of the second electrode 22, and the electrode connection portion 42 of the cover 40 can be soldered to the current collector 31.

[0146] In another embodiment of this disclosure, the electrode connection portion 42 can be directly and electrically connected to the tab of the second electrode 22.

[0147] Specifically, the tabs of the second electrode 22 can be welded and electrically connected to the electrode connection portion 42 of the cover 40 without the need for a separate current collector. That is, since the cover 40 can be attached to the battery housing 10 to cover the open end of the battery housing 10, and is also electrically connected to the electrode assembly 20, a separate current collector (such as a negative current collector) is not required. In other words, the cover 40 of this disclosure can also be provided as a so-called integrated cover capable of simultaneously performing the function of a current collector. Therefore, the joint between the cover 40 and the battery housing 10 can be simplified, and the current collector 31 is not required to electrically connect the electrode assembly 20 to the cover 40, thereby reducing the number of parts and assembly work, ensuring more internal volume, and further increasing energy density.

[0148] In embodiments of this disclosure, the junction between the electrode connection portion 42 and the tab of the second electrode 22 can extend in the radial direction. That is, the electrode connection portion 42 can extend toward the flat portion 43 and the support surface 45. Specifically, the electrode connection portion 42 can extend toward the flat portion 43 in the centripetal direction, and the electrode connection portion 42 can extend radially toward the support surface 45. In this case, since the welding length (foil cover tab weld (LFW)) between the electrode connection portion 42 and the metal foil 23 can be ensured to be long, the internal resistance of the battery cell can be reduced.

[0149] In embodiments of this disclosure, a plurality of electrode connections 42 may be arranged radially relative to the center of the cover 40 and spaced apart from each other at equal intervals in the circumferential direction.

[0150] In embodiments of this disclosure, three electrode connection portions 42 may be provided at 120° intervals.

[0151] In embodiments of this disclosure, three electrode connection portions 42 may be provided. With three electrode connection portions 42, the multiple electrode connection portions 42 can form a single plane, making it easier to ensure a stable, flat surface with the electrode assembly 20. Furthermore, the cover 40 can ensure bonding strength through welding points that only partially contact the slotted tab 27 of the second electrode, and can also ensure that the cover 40 resists bulging due to internal pressure of the battery cell.

[0152] In embodiments of this disclosure, the cover 40 may further include one or more bridges 44. There may be multiple bridges 44, for example, three. Bridges 44 may extend radially from the flat portion 43. Bridges 44 may be formed to separate two adjacent electrode connection portions 42. Bridges 44 may extend from the flat portion 43 toward the abutment surface 41.

[0153] In embodiments of this disclosure, the bridge 44 allows the plurality of electrode connections 42 to be more securely separated and disconnected. As described above, the bridge 44 can enhance the rigidity of the cover 40.

[0154] In embodiments of this disclosure, although the upper surface of the bridge 44 is formed to be axially outward compared to the upper surface of the electrode connection portion 42, it can be formed to be axially inward compared to the upper surface of the flat portion 43. When the bridge 44 is formed in this manner, the rigidity of the cover 40 can be further enhanced.

[0155] In embodiments of this disclosure, the protrusion height of the bridge 44 may correspond to or be less than the protrusion height of the support surface 45.

[0156] In embodiments of this disclosure, the protrusion height of the bridge 44 can correspond to the protrusion height of the support surface 45, such that they form a single plane. In this case, when the battery housing 10 is placed upright and the cover 40 of the battery housing 10 faces the ground, the bridge 44 and the support surface 45 can also contact the ground.

[0157] In embodiments of this disclosure, if the height of the bridge 44 is less than the height of the support surface 45, the support surface 45 may provide an annular support surface.

[0158] In embodiments of this disclosure, the cover 40 may also include an injection hole 46 at the center of the cover 40. With the open end of the battery housing 10 covered by the cover 40, the injection hole 46 may be aligned with the central winding hole of the electrode assembly 20 housed in the battery housing 10.

[0159] In embodiments of this disclosure, such as Figure 9 As shown in other accompanying drawings, the injection hole 46 may be provided on the bottom surface of the cover 40, that is, on the flat portion 43 that protrudes axially outward beyond the electrode connection portion 42 of the cover 40. The height of the flat portion 43 may be less than the height of the support surface 45. The flat portion 43 may be connected to the radial inner edge of the electrode connection portion 42 and may extend axially outward as the flat portion 43 approaches radially inward.

[0160] In embodiments of this disclosure, such as Figure 11 As shown in the other accompanying drawings, the injection port 46 can be closed by a cap 50 covering the injection port 46. The edge of the cap 50 can seal against the edge of the injection port 46. This seal can be achieved by seam welding or other known sealing methods.

[0161] In embodiments of this disclosure, the cap 50 may be in the form of a plug and may be formed by deep drawing a thin metal sheet of 0.3 mm.

[0162] In embodiments of this disclosure, with the injection hole 46 covered by the cap 50, the height of the cap 50 can be less than the height of the support surface 45. Since the cap 50 is also positioned below the support surface 45, it does not bear direct load even when the battery cell is placed upright and the cap 40 is in contact with the ground.

[0163] In embodiments of this disclosure, the flat portion 43 protrudes axially outward beyond the bottom of the cap (i.e., the electrode connection portion 42). Therefore, the edge of the injection hole 46 is positioned separate from the slotted tab 27 of the second electrode 22. Thus, when electrolyte is injected through the injection hole 46, the injection hole 46 is covered with the cap 50, and it is joined by welding or other methods, the effects of the sealing process of the cap 50 on battery performance (such as heat transfer to the electrode assembly 20 and damage to the separator) can be minimized.

[0164] Meanwhile, in another embodiment of this disclosure, the cover 40 may not include a separate injection hole. In this case, when manufacturing the battery cell, if there is no separate injection hole, such as in the bottom 12 of the battery housing 10, the electrolyte injection process can be performed before covering the battery housing 10 with the cover 40.

[0165] However, when the cap 40 also includes an injection hole 46, electrolyte can be injected through the injection hole 46 even after the cap 40 is press-fitted into the battery housing 10 and the weld portion W and the joint portion M are formed. This prevents the electrolyte from being affected by the heat of the joint compared to joining the cap 40 to the battery housing 10 after the electrolyte has been injected. In addition, when the cap 50 is joined to the edge of the injection hole 46, the upward protrusion of the flat portion 43 reduces the possibility of the electrolyte being affected by the heat of the joint of the cap 50.

[0166] In embodiments of this disclosure, the injection hole 46 formed in the center of the cover 40 can also be used as a channel for a device for welding the current collector 31 of the first electrode terminal 13 and the first electrode 21.

[0167] Therefore, even after the cover 40 is joined to the battery housing 10, a welding device can be inserted into the battery housing 10 through the injection hole 46, thereby joining the first electrode 21 and the first electrode terminal 13.

[0168] In embodiments of this disclosure, the flat portion 43 may further include a mounting portion 43a, which is axially recessed inward and extends radially in a flat shape. In embodiments of this disclosure, the configuration of the mounting portion 43a can minimize interference with the electrolyte when the cap 50 is welded to the injection port 46.

[0169] In embodiments of this disclosure, increasing the length of the mounting portion 43a formed between the injection hole 46 and the flat portion 43 can improve the solderability of the cap 50.

[0170] In embodiments of this disclosure, an exhaust portion 60 may be formed in the cover 40. When a thermal event occurs in the battery cell, the exhaust portion 60 may rupture due to the internal pressure of the high-temperature exhaust gas, thereby allowing the exhaust gas to be discharged from the battery cell to the outside.

[0171] In embodiments of this disclosure, the cover 40 may include a support surface 45 that extends radially in a flat shape at the radially inward portion of the abutment surface 41, and an electrode connection portion 42 may be disposed radially inward of the support surface 45 and axially recessed, and an exhaust portion 60 may be disposed in the support surface 45.

[0172] In embodiments of this disclosure, the venting portion 60 may be disposed radially outside the electrode connection portion 42 along the circumferential direction. By slotting the two surfaces of the support surface 45, the venting portion 60 may be implemented as a flexible or thin portion.

[0173] In embodiments of this disclosure, the vent 60 has sufficient strength to prevent deformation under the force applied when the cover 40 is press-fitted into the battery housing 10. When the internal pressure of the battery housing 10 surges due to a short circuit or the like, the vent 60 breaks to separate the electrode connection 42 of the cover 40 from the abutment surface 41 of the cover 40. Therefore, the electrical connection between the electrode connection 42 of the tab connected to the second electrode 22 and the battery housing 10 can be severed, and the internal space of the battery housing 10 can be opened to the outside, thereby releasing the gas that causes internal pressure.

[0174] In embodiments of this disclosure, the vent 60 may be located near the center of the support surface 45. In this case, even if the support surface 45 is pressurized, the pressure is transmitted to the inclined surface connected to the electrode connection portion 42 and does not affect the vent 60. Therefore, the force applied when the cover 40 is joined to the battery housing 10 and the electrode assembly 20 may not deform the vent 60.

[0175] In embodiments of this disclosure, the exhaust portion 60 may be positioned radially outward than the bridge 44. Then, the bridge 44 may be provided between the electrode connections 42 in the circumferential direction.

[0176] In the embodiments of this disclosure, when the internal pressure of the battery casing 10 increases, the pressure is smoothly transmitted in the circumferential direction to the lower space of the bridge 44 disposed between the electrode connection portions 42, and serves as a force to lift the bridge 44 upward. Furthermore, this force is concentrated at three locations along the circumferential direction. Therefore, the internal pressure of the battery casing 10 can be smoothly transmitted to the vent portion 60, thereby causing the vent portion 60 to rupture smoothly.

[0177] In embodiments of this disclosure, the burst pressure of the battery casing 10 can be controlled by controlling the venting portion 60 and its width. For example, the venting portion 60 can be configured such that when the pressure inside the battery casing 10 falls below 15 kgf / cm², the burst pressure is controlled. 2 Up to 35 kgf / cm 2 The vent 60 ruptures when the pressure inside the battery housing 10 increases abnormally, thereby releasing all internal gases to the outside. The vent 60 can be formed by slotting the cover 40 to partially reduce its thickness. The vent 60 can have a thickness gradient. A thickness gradient means that, when viewed in cross-section, the vent 60 is formed at an angle relative to a predetermined horizontal plane.

[0178] In embodiments of this disclosure, the vent 60 may be implemented as a thin portion on the support surface 45. However, the vent 60 formed by the cover 40 is not limited thereto. For example, the vent may be provided in the cap 50 covering the injection hole 46, the vent may be configured at the joint between the injection hole 46 and the cap 50, or the vent may be configured at the joint M between the cover 40 and the battery housing 10.

[0179] A hole may be formed in the center of the bottom 12 of the battery housing, and a first electrode terminal 13 may be fitted into the hole. The first electrode terminal 13 may be riveted and secured to the bottom 12, and a terminal washer 14 may be inserted between the first electrode terminal 13 and the bottom 12. The terminal washer 14 may be inserted between the first electrode terminal 13 and the bottom 12 to seal the inside and outside of the battery housing 10, thereby preventing electrolyte leakage and electrically insulating the first electrode terminal 13 and the bottom 12 from each other.

[0180] However, the connection method between the first electrode terminal 13 and the bottom 12 is not limited to this. For example, various other fixing methods such as bolt-nut joint, glass sealing, chrome plating, and PP-MAH heat bonding are also applicable, which can seal the gap between the first electrode terminal 13 and the bottom 12 and electrically insulate them.

[0181] The first electrode terminal 13 may have a first polarity, and the battery casing 10 may have a second polarity. Therefore, both the bottom 12 of the battery casing 10 and the sidewall 11 connected thereto may have a second polarity.

[0182] Therefore, the battery housing 10 may have both a first electrode terminal 13 and a second electrode terminal 15 located at one axial end. In this case, the battery housing 10 may have both a busbar located at one axial end of the battery housing 10 and connected to the first electrode terminal 13 and a busbar connected to the second electrode terminal 15.

[0183] In embodiments of this disclosure, the first electrode terminal 13 may be a positive terminal and the second electrode terminal 15 may be a negative terminal, or vice versa.

[0184] Reference Figure 12 The battery 1 with the aforementioned cover can be housed in the casing 71 of the battery pack 70. The battery pack 70 can be configured using a battery module as an intermediate component, or it can be configured directly without a battery module, as shown in the figure.

[0185] Because the battery 1 itself has a large volume, there is no particular difficulty in realizing the battery pack 70 even without using an intermediate structure called a battery module. Furthermore, since the second electrode of the battery 1 is connected via a cover, the battery can have low internal resistance and high energy density. Additionally, since the vent 60 is located within the cover 40 and does not occupy separate space, energy density can be further ensured. Therefore, the energy density of the battery pack 70 equipped with the battery 1 can be achieved at an even higher level.

[0186] The battery pack 70 with this increased energy density can store the same amount of energy while reducing its size and weight. Therefore, when the battery pack 70 equipped with this battery 1 is installed in a vehicle 80 that uses electricity as its energy source, such as Figure 13 As shown, the mileage per unit of energy of the vehicle can be further increased.

[0187] The previously disclosed embodiments should be considered as being intended to describe embodiments of this disclosure, and not to limit them. Therefore, the scope of this disclosure, as defined by the appended claims rather than the detailed description above, should be interpreted to include the claims and all modifications and variations derived from equivalent concepts of this disclosure.

[0188] As described above, although this disclosure has been described with reference to limited embodiments and accompanying drawings, this disclosure is not limited thereto, and various modifications and variations are possible for those skilled in the art to which this disclosure pertains without departing from the technical concept of this disclosure and the equivalent scope of the appended claims. Therefore, the above embodiments should be considered illustrative rather than restrictive. That is, the true scope of this disclosure is defined by the claims, and all variations or modifications equivalent to them should be interpreted as falling within the scope of this disclosure.

[0189] In the following description, although the present disclosure will be described in more detail by way of embodiments, the following embodiments are provided for illustrative purposes only, and the scope of the present disclosure is not limited thereto.

Claims

1. A battery, the battery comprising: A battery housing having a sidewall, a bottom connected to one axial end of the sidewall, and an open end disposed at the other axial end of the sidewall; An electrode assembly having a first electrode, a second electrode, and a diaphragm inserted between the first electrode and the second electrode, the first electrode, the second electrode, and the diaphragm being wound around a winding axis and housed inside the battery casing such that the tab of the second electrode faces the open end; as well as A cover, configured to cover the open end of the battery housing and electrically connected to the second electrode, Specifically, a first inclined portion is formed at the other axial end of the sidewall, such that the inner diameter of the battery casing increases in the axial outward direction. Specifically, an abutment surface is formed on the outer peripheral surface of the cover, such that the outer diameter of the cover increases outward in the axial direction, and Wherein, at least a portion of the abutting surface contacts and is connected to the first inclined portion.

2. The battery according to claim 1, in, The abutting surface of the cover and the first inclined portion of the battery casing fit together without gaps.

3. The battery according to claim 1, in, When viewed in a cross section parallel to the axial direction, the inclination of the abutting surface is substantially the same as the inclination of the first inclined portion.

4. The battery according to claim 1, in, When viewed in a cross section parallel to the axial direction, the abutting surface has an inclination of 1° to 45° relative to the axial direction.

5. The battery according to claim 1, in, The abutting surface of the cover and the first inclined portion of the battery casing are welded together to form a welded portion.

6. The battery according to claim 5, in, Based on 100% of the area of ​​the first inclined portion, the welded portion is formed to cover 90% to 100% of the area of ​​the first inclined portion.

7. The battery according to claim 1, in, The abutting surface of the cover includes an inclined abutting surface and a vertical abutting surface.

8. The battery according to claim 1, in, The battery casing includes a horizontal portion, which is connected to the first inclined portion and is perpendicular to the axial direction. The horizontal portion of the cover is substantially without steps at the point where it contacts the outer surface of the cover.

9. The battery according to claim 1, in, The first inclined portion is formed by a trimming process for the battery casing.

10. The battery according to claim 1, in, The cover includes an electrode connection portion electrically connected to the tab of the second electrode.

11. The battery according to claim 10, in, The electrode connection portion is located at a position that is recessed from the radially inner side of the abutting surface toward the axially inner side.

12. The battery according to claim 10, in, The electrode connections are arranged at equal intervals in the circumferential direction.

13. The battery according to claim 1, in, The cover includes an exhaust section.

14. The battery according to claim 1, in, An injection hole is provided at the center of the cover.

15. The battery according to claim 1, in, The bottom of the battery casing has a first electrode terminal, which is configured to be electrically insulated from and fixed to the bottom. The first electrode of the electrode assembly is electrically connected to the first electrode terminal.

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

17. A vehicle comprising a battery pack according to claim 16.

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