Battery, and battery pack and vehicle comprising same

Abstract

The present invention provides a battery pack characterized by comprising: a battery housing having a side wall member, a bottom member connected to one end of the side wall member in the axial direction, and an open portion provided at the other end of the side wall member 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 portion; and a lid seated on the outer surface of the other end of the side wall member in the axial direction so as to cover the open portion of the battery housing, wherein a coupling portion is formed such that the edge of the inner surface of the lid and the edge of the other end of the side wall member in the axial direction are bonded to each other, and the coupling portion is recessed inward in the radial direction.

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. 10-2024-0088247, filed July 4, 2024, and Korean Patent Application No. 10-2025-0073787, filed June 5, 2025, the entire contents of which are incorporated herein by reference.

[0003]

[0004] Secondary batteries are highly applicable across a wide range of product categories and boast superior electrical properties, including high energy density. Their applications extend beyond portable electronic devices to include electric vehicles (EVs) and hybrid electric vehicles (HEVs). Secondary batteries not only offer a dramatic reduction in fossil fuel consumption, but are also environmentally friendly, producing no harmful byproducts from energy use. They are also attracting attention as an alternative energy source for improving energy efficiency.

[0005] Currently widely used secondary batteries include lithium-ion batteries, lithium polymer batteries, nickel-cadmium batteries, nickel-hydrogen batteries, and nickel-zinc batteries, and the operating voltage of these secondary battery cells generally ranges from approximately 2.5 V to 4.5 V. When a higher output voltage is required, multiple battery cells are connected in series to form a battery module or battery pack, and multiple cells are also connected in parallel depending on the required charge / discharge capacity. Accordingly, the number of batteries included in a battery pack or module and the electrical connection type can be set in various ways depending on the required voltage and capacity conditions.

[0006] The shape of secondary battery cells is classified into cylindrical, square, and pouch types. In the case of cylindrical batteries, an electrode assembly with a separator between positive and negative plates is wound in the form of a jelly roll, and then housed together with an electrolyte in a battery housing to form a battery. In some embodiments, one side of the battery housing may be open, and a lid may be welded to the open end to seal it. However, if the contact area between the battery housing and the lid is insufficient, the weldability may be reduced, which may lower the welding strength or lead to problems such as electrolyte leakage.

[0007] Accordingly, research is currently underway on seam welding, a method for joining leads and battery housings, instead of beading and crimping. Seam welding is a process for joining battery housings and leads, and welding can be performed in a direction parallel to or perpendicular to the housing's axis. However, when welding is performed in a direction perpendicular to the axis, a weld bead is formed at the weld site, causing an uneven outer diameter of the battery housing. This deviation in outer diameter can affect the contact area with the heat sink within the battery pack, which can lead to a decrease in heat dissipation performance and a decrease in the performance of the entire vehicle.

[0008]

[0009] The present invention is intended to solve the problems of the prior art as described above, and aims to provide a battery that can prevent the phenomenon of the outer diameter of the battery housing becoming uneven due to the welding bead during the manufacturing process of a cylindrical secondary battery including a seam welding process, and consequently secure the stability of contact between the battery and the heat sink, thereby preventing the deterioration of the heat dissipation performance of the battery pack and the performance of the entire system.

[0010] In addition, another object of the present invention is to improve the precision of the external shape of the battery housing, reduce the product defect rate, and secure the stability and reliability of the production process by minimizing or uniformizing the influence of the welding bead formed at the joint between the lead and the battery housing on the outer diameter of the battery housing.

[0011] 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.

[0012] To achieve this purpose, according to one aspect of the present invention, a battery of the following embodiment, and a battery pack and a vehicle including the same are provided.

[0013] According to a first embodiment, a battery is provided, which comprises a battery housing having a side wall member, a bottom member connected to one axial end of the side wall member, and an opening provided at the other axial end of the side wall member; 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 opening; and a lid that is seated on an outer surface of the other axial end of the side wall member and covers the opening of the battery housing, and a joining portion is formed such that an edge of an inner surface of the lid and an edge of the other axial end of the side wall member are joined, and the joining portion is characterized in that it is recessed radially inward.

[0014] According to a second embodiment, in the first embodiment, the lead and the side wall member are joined by welding, the joint portion is formed with a weld bead by the welding, and the weld bead may not protrude radially outwardly of the battery housing.

[0015] According to a third embodiment, in any one of the first to second embodiments, the connecting portion may be provided in a closed loop shape along the circumferential direction.

[0016] According to a fourth embodiment, in any one of the first to third embodiments, the radial diameter of the lead and the radial diameter of the axial other end of the battery housing may be the same.

[0017] According to a fifth embodiment, in any one of the first to fourth embodiments, the axial other end of the side wall member may have a first inclined portion on the radially outer side and a first flat portion connected to the first inclined portion and perpendicular to the side wall member.

[0018] According to the sixth embodiment, in the fifth embodiment, the first inclined portion may extend radially outward as it goes axially inward.

[0019] According to the seventh embodiment, in any one of the fifth to sixth embodiments, the angle (α) between the first inclined portion and the first flat portion may be 100° or more and 170° or less.

[0020] According to the eighth embodiment, in any one of the fifth to seventh embodiments, the radial length of the first inclined portion may be smaller than the radial length of the first flat portion.

[0021] According to a ninth embodiment, in any one of the first to eighth embodiments, the edge of the inner surface of the lead may have a second inclined portion radially outward, and a second flat portion connected to the second inclined portion and perpendicular to the axial direction.

[0022] According to the tenth embodiment, in the ninth embodiment, the second inclined portion may extend radially outward as it goes axially outward.

[0023] According to the eleventh embodiment, in any one of the ninth to tenth embodiments, the radial length of the second inclined portion may be smaller than the radial length of the second flat portion.

[0024] According to the 12th embodiment, in any one of the 9th to 11th embodiments, the angle (β) between the second inclined portion and the second flat portion may be 100° or more and 170° or less.

[0025] According to a 13th embodiment, in any one of the first to twelfth embodiments, the lead may further include a vent notch.

[0026] According to a 14th embodiment, in any one of the 1st to 13th embodiments, a second collector plate connected to the second electrode may be further included, wherein the second collector plate may be coupled to the battery housing.

[0027] According to the 15th embodiment, in the 14th embodiment, the lead may be axially spaced from the second collector plate on the radially outer side.

[0028] According to a 16th embodiment, a battery pack is provided including a battery according to any one of the 1st to 15th embodiments.

[0029] According to a seventeenth embodiment, a vehicle is provided including a battery pack according to the sixteenth embodiment.

[0030]

[0031] According to one embodiment of the present invention, a battery can prevent uneven outer diameters of the battery housing due to weld beads in a battery manufacturing process involving a seam welding process, thereby ensuring stable contact between the battery and the heat sink. Accordingly, deterioration of the heat dissipation performance of the battery pack can be effectively prevented.

[0032] In addition, by minimizing or uniformizing the influence of the welding bead formed at the joint between the lead of the present invention and the battery housing on the outer diameter of the battery housing, the precision of the outer shape of the battery housing can be improved and the product defect rate can be reduced.

[0033] In addition, since the battery of the present invention performs side welding through a joint formed on the side, damage to the electrode assembly can be minimized.

[0034] 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.

[0035] 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.

[0036] Figure 1 illustrates a battery according to one aspect of the present invention.

[0037] Figure 2a illustrates a battery according to one aspect of the present invention.

[0038] Figure 2b illustrates a battery according to one aspect of the present invention.

[0039] Figure 3a shows a cross-section of a battery according to one aspect of the present invention.

[0040] Figure 3b illustrates a side wall member of a battery according to one aspect of the present invention.

[0041] Figure 3c illustrates a lead of a battery according to one aspect of the present invention.

[0042] Figure 4 shows a cross-section of a battery according to another aspect of the present invention.

[0043] Figure 5 shows a cross-section of a battery according to another aspect of the present invention.

[0044] Figure 6 shows a cross-section of a battery according to one aspect of the present invention.

[0045] Figure 7 illustrates an electrode assembly according to one aspect of the present invention.

[0046] Figure 8 illustrates an electrode assembly according to one aspect of the present invention.

[0047] FIG. 9 illustrates a jelly-roll type electrode assembly according to one aspect of the present invention.

[0048] FIG. 10 illustrates a jelly-roll type electrode assembly according to one aspect of the present invention.

[0049] Fig. 11 illustrates a battery according to one aspect of the present invention.

[0050] Figure 12 illustrates a battery according to one aspect of the present invention.

[0051] Figure 13 illustrates a battery according to one aspect of the present invention.

[0052] Fig. 14 illustrates a second collector plate according to one aspect of the present invention.

[0053] Fig. 15 illustrates a second collector plate according to one aspect of the present invention.

[0054] Figure 16 schematically illustrates a process of storing an electrode assembly according to one aspect of the present invention in a battery housing.

[0055] Figure 17 schematically illustrates a process of welding a first electrode terminal and a first collector plate according to one aspect of the present invention.

[0056] Figure 18 illustrates a battery pack according to one aspect of the present invention.

[0057] Fig. 19 illustrates a battery pack according to one aspect of the present invention.

[0058] Figure 20 illustrates a vehicle according to one aspect of the present invention.

[0059]

[0060] 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.

[0061] 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.

[0062] Justice

[0063] 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.

[0064] Throughout this specification, unless otherwise specifically stated, each component may be singular or plural.

[0065] 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.

[0066] 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.

[0067] 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.

[0068] 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.

[0069] 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.

[0070]

[0071] The present invention provides a battery.

[0072] According to one aspect of the present invention, the battery (1) of the present invention comprises a battery housing (10) having a side wall member (11), a bottom member (12) connected to one axial end of the side wall member (11), and an opening provided at the other axial end of the side wall member (11); an electrode assembly (20) in which a first electrode (21) and a second electrode (22) and a separator (28) interposed therebetween are wound around a winding axis, and a tab of the second electrode (22) is accommodated inside the battery housing so that it faces the opening; And it includes a lead (40) that is seated on the outer surface of the axial other end of the side wall member (11) and covers the opening of the battery housing, and a connecting portion (16) is formed so that the edge of the inner surface of the lead (40) and the edge of the axial other end of the side wall member (11) are joined, and the connecting portion (16) is characterized in that it is recessed radially inward.

[0073] Below, this is explained in more detail.

[0074]

[0075] The battery (1) of the present invention may be, for example, a cylindrical battery (1) having a form factor ratio (defined as the ratio of the diameter (Φ) to the height (H) of a cylindrical battery cell divided by the height) of approximately 0.4 or greater.

[0076] Here, the form factor refers to a value indicating the diameter and height of a cylindrical battery (1). Cylindrical batteries to be applied to a pressure tester may be, for example, 46110 cells, 48750 cells, 48110 cells, 48800 cells, and 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 last number 0 indicates that the cross-section of the cell is circular.

[0077] The battery (1) to be applied to the pressure tester may be a cylindrical battery (1) having a roughly cylindrical cell shape, a diameter of approximately 46 mm, a height of approximately 110 mm, and a form factor ratio of 0.418.

[0078] A battery (1) according to another embodiment may be a cylindrical battery cell having a roughly cylindrical shape, a diameter of about 48 mm, a height of about 75 mm, and a form factor ratio of 0.640.

[0079] According to another embodiment, a battery (1) may be a cylindrical battery cell having a roughly cylindrical shape, a diameter of about 48 mm, a height of about 110 mm, and a form factor ratio of 0.418.

[0080] According to another embodiment, a battery (1) may be a cylindrical battery cell having a roughly cylindrical shape, a diameter of about 48 mm, a height of about 80 mm, and a form factor ratio of 0.600.

[0081] According to another embodiment, a battery (1) may be a cylindrical battery cell having a roughly cylindrical shape, a diameter of about 46 mm, a height of about 80 mm, and a form factor ratio of 0.575.

[0082] 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.

[0083] Referring to FIG. 1, the battery housing (10) of the present invention has a cylindrical side wall member (11), a bottom member (12) connected to one axial end of the side wall member (11), and an opening provided at the other axial end of the side wall member (11).

[0084] The above-mentioned bottom member (12) and the above-mentioned side wall member (11) can be manufactured by forming a conductive metal sheet using a deep drawing process, and trimming the front end of the side wall member (11) with a punch while holding it with a blank holder.

[0085] Alternatively, the above-mentioned bottom member (12) and the above-mentioned side wall member (11) can be manufactured by forming a conductive metal sheet through a deep drawing process, supporting the front end of the side wall member (11) through a jig, and then processing it with a cutting means so that it is perpendicular to the above-mentioned bottom member (12).

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

[0087] A hole is formed in the center of the bottom member (12), and a first electrode terminal (13) can be fitted into the hole. The first electrode terminal (13) can be fixed to the bottom member (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 member (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 member (12).

[0088] However, the method of connecting the first electrode terminal (13) and the bottom member (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 member (12) and electrically insulate the first electrode terminal (13) and the bottom member (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.

[0089] The first electrode terminal (13) may have a first polarity, and the battery housing (10) may have a second polarity. Accordingly, both the bottom member (12) of the battery housing (10) and the side wall member (11) connected thereto may have a second polarity.

[0090] 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).

[0091] 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.

[0092]

[0093] In one embodiment of the present invention, the lead (40) can be manufactured by pressing and forming a circular metal sheet.

[0094] In one embodiment of the present invention, the lead (40) has a substantially disc shape so as to be seated on the outer surface of the axial other end to block the opening of the battery housing (10).

[0095] Referring to Fig. 2a, a connecting portion (16) is formed so that the edge of the inner surface of the lead (40) and the edge of the axial end of the side wall member (11) are joined, and the connecting portion (16) is recessed radially inward.

[0096]

[0097] As shown in Fig. 3a, the battery (1) of the present invention is recessed radially inward at the portion where the lead (40) and the side wall member (11) come into contact.

[0098] Figure 3b illustrates a side wall member (11) according to one aspect of the present invention.

[0099] Referring to Fig. 3b, the axial end of the side wall member (11) may have a first inclined portion (111) on the radially outer side and a first flat portion (112) connected to the first inclined portion and perpendicular to the side wall member.

[0100] In one embodiment of the present invention, the axial other end of the side wall member (11) may have a first inclined portion (111) on the radially outer side and a first flat portion (112) connected to the first inclined portion (111) and perpendicular to the side wall member. That is, the first inclined portion (111) may be connected to the outer circumferential surface of the side wall member (11), and the first flat portion (112) may be connected to the first inclined portion (111) and connected to the inner circumferential surface of the side wall member (11).

[0101] In one embodiment of the present invention, the first inclined portion (111) may extend radially outward as it goes axially inward. That is, the first inclined portion (111) may have a surface whose outer diameter increases radially outward as it goes axially inward. At this time, the first inclined portion (111) may be a flat surface or a curved surface.

[0102] When the first inclined portion (111) is a plane, the angle (α) between the first inclined portion (111) and the first flat surface is not limited, but may be, for example, 100° to 170°, 105° to 165°, 110° to 160°, 115° to 155°, 120° to 150°, 125° to 145°, 130° to 140°, or 45°.

[0103] In one embodiment of the present invention, the first inclined portion (111) may be in a chamfered shape, a rounded shape, or an oblique inclined shape formed by a cutting means.

[0104] In one embodiment of the present invention, the radial length of the first inclined portion (111) may be smaller than the radial length of the first flat portion (112). In this case, the contact area between the side wall member (11) and the lead (40) is sufficiently guaranteed, so that the welding strength can be excellent.

[0105]

[0106] Figure 3c illustrates a lead (40) according to one aspect of the present invention.

[0107] Referring to FIG. 3c, the edge of the inner surface of the lead (40) may have a second inclined portion (401) on the radially outer side and a second flat portion (402) connected to the second inclined portion (401) and perpendicular to the axial direction.

[0108] In one embodiment of the present invention, the second inclined portion (401) may extend radially outward as it goes axially outward. That is, the second inclined portion (401) may have a surface whose outer diameter increases radially outward as it goes axially outward. At this time, the second inclined portion (401) may be a flat surface or a curved surface.

[0109] In one embodiment of the present invention, when the second inclined portion (401) is a plane, the angle (β) between the second inclined portion (401) and the second flat portion (402) is not limited, but may be, for example, 100° to 170°, 105° to 165°, 110° to 160°, 115° to 155°, 120° to 150°, 125° to 145°, 130° to 140°, or 45°.

[0110] In one embodiment of the present invention, the second inclined portion (401) may be in a chamfered shape, a rounded shape, or an oblique inclined shape formed by a cutting means.

[0111] In one embodiment of the present invention, the radial length of the second inclined portion (401) may be smaller than the radial length of the second flat portion (402). In this case, the contact area between the side wall member (11) and the lead (40) is sufficiently guaranteed, so that the welding strength can be excellent.

[0112] In one embodiment of the present invention, the connecting portion (16) may be formed by both the first inclined portion (111) of the battery housing (10) and the second inclined portion (401) of the lead (40), as shown in FIG. 3a.

[0113] In another embodiment of the present invention, the connecting portion (16) may be formed only with the first inclined portion (111) of the battery housing (10), as shown in FIG. 4, and the second inclined portion (401) of the lead (40) may not be formed.

[0114] In another embodiment of the present invention, the connecting portion (16) may be formed such that the first inclined portion (111) of the battery housing (10) is not formed, and only the second inclined portion (401) of the lead (40) is formed, as shown in FIG. 5.

[0115] In one embodiment of the present invention, the angle (γ) between the side wall member (11) of the battery housing (10) and the lead (40) at the connecting portion (16) may be, for example, 10° to 170°, 20° to 160°, 30° to 150°, 40° to 140°, 50° to 130°, 60° to 120°, 70° to 110°, 80° to 100° or 90°.

[0116]

[0117] In one embodiment of the present invention, the connecting portion (16) may be formed in a closed loop shape along the circumferential direction as illustrated in FIG. 2A. That is, the connecting portion (16) may be formed continuously between the battery housing (10) and the lead (40). In this case, the mechanical bonding force between the battery housing (10) and the lead (40) may be further enhanced.

[0118] In another embodiment of the present invention, the connecting portion (16) may be formed discontinuously between the battery housing (10) and the lead (40). In this case, the connecting portion (16) may be formed regularly or irregularly along the circumferential direction.

[0119] In one embodiment of the present invention, the radial diameter of the lead (40) and the radial diameter of the other axial end of the battery housing (10) may be the same. In this case, the same includes “substantially the same,” and the “substantially the same” may mean that the radial diameter of the lead (40) is within a range of 95% to 105% of the radial diameter of the other axial end of the battery housing (10) of 100%. In addition, the radial diameter of the other axial end of the battery housing (10) may be within a range of 95% to 10% of the radial diameter of the lead (40) of 100%.

[0120]

[0121] Figure 6 shows a cross-section of a battery in which a lead and a side wall member are welded according to one aspect of the present invention.

[0122] Referring to Fig. 6, the lead (40) and the side wall member (11) are joined by welding, and the joint portion has a weld bead (16a) formed by the welding, and the weld bead (16a) may not protrude radially outwardly of the battery housing. That is, the weld bead (16a) may not protrude outside the outer diameter of the lead (40) and / or outside the outer diameter of the battery housing (10). In other words, the weld bead (16a) may be located inside the outer diameter of the lead (40) and the outer diameter of the battery housing (10).

[0123] In this case, the outer diameter of the battery housing (10) can be maintained constant, and the phenomenon of unevenness can be prevented, thereby ensuring contact stability between the battery and the heat sink.

[0124] Meanwhile, the connection between the lead (40) and the side wall member (11) can be made by resistance welding, ultrasonic welding, laser welding, or other methods.

[0125] In one embodiment of the present invention, the lead (40) may further include a vent notch (41).

[0126] For example, as illustrated in FIG. 3A, the vent notch (41) may be formed on the upper surface and / or lower surface of the lead (40). The vent notch (41) may be ruptured by the internal pressure of high-temperature venting gas when a thermal event occurs in the battery, thereby allowing the venting gas to be discharged to the outside from the battery.

[0127]

[0128] In one embodiment of the present invention, the lead (40) of the present invention may further include a liquid filler port (42) at the center of the lead (40) as illustrated in FIG. 2b. With the open end of the battery housing (10) covered by the lead (40), the liquid filler port (42) may be aligned with the core hollow portion of the electrode assembly (20) accommodated in the battery housing (10).

[0129] In one embodiment of the present invention, the injection hole (42) may be formed radially inside the vent notch (41), and preferably may be formed in the center.

[0130] In one embodiment of the present invention, the liquid injection port (42) may be closed by covering a plug (50) as illustrated in FIGS. 2a and 2b. The rim of the plug (50) may be sealed with the rim of the liquid injection port (42). The sealing may be achieved by seam welding or by applying various other known sealing methods.

[0131] 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.

[0132] 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 member (12) of the battery housing (10), the electrolyte filling process may be performed first before covering the battery housing (10) with the lead (40).

[0133] However, if the lead (40) further includes a liquid injection port (42), the electrolyte can be injected through the liquid injection port (42) even after the lead (40) is pressed into the battery housing (10) and a welded portion and a joint are formed. Then, compared to joining the lead (40) to the battery housing (10) in a liquid injection state, the heat of the joining can be prevented from affecting the electrolyte at all.

[0134] In one embodiment of the present invention, on the other hand, the injection hole (42) 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 first current collector plate (31) of the first electrode (21) can pass.

[0135] 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 (42).

[0136]

[0137] In one embodiment of the present invention, an electrode assembly (20) is accommodated within the battery housing (10). The electrode assembly (20) is prepared by preparing a first electrode (21), a second electrode (22), and a separator (28) having a predetermined width and extending in the longitudinal direction as illustrated in FIG. 7, 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. 8, and then winding the laminate around a core shaft as illustrated in FIG. 9, in the form of a jelly-roll.

[0138] 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.

[0139] 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.

[0140]

[0141] 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.

[0142] 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.

[0143] 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.

[0144] 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.

[0145] 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.

[0146] 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.

[0147] 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 whiskers 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).

[0148] In addition, the positive electrode active material layer may optionally further include a dispersant as needed.

[0149] 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.

[0150] 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.

[0151] 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.

[0152] 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.

[0153] 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.

[0154] 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.

[0155]

[0156] 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. 7 and 8. The non-conductive portion (26) itself may function as an electrode tab.

[0157] 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).

[0158] In one embodiment of the present invention, the notching tabs (27) may be in the shape of an equilateral trapezoid as illustrated in FIGS. 7 and 8. However, their shapes may be various shapes such as a semicircle, a semi-ellipse, a triangle, a rectangle, a parallelogram, etc.

[0159] 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.

[0160] 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.

[0161] 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.

[0162]

[0163] 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. 9 and 10 , the notched tab (27) can be bent radially inward.

[0164] 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.

[0165] 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. 10.

[0166] In one embodiment of the present invention, a first 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. 11.

[0167] In one embodiment of the present invention, the first collector plate (31) can be manufactured by punching, trimming, piercing, and bending a metal sheet. The first collector plate (31) can be made of aluminum.

[0168] In one embodiment of the present invention, referring to FIG. 11, the first current collector plate (31) may include a terminal connection portion (311) extending radially from a center portion, a ring portion (312) connecting a centrifugal edge of the terminal connection portion (311) in a circumferential direction, and an electrode connection portion (313) extending centripetally from the ring portion (312) but not connected to the terminal connection portion (311). The center portion of the terminal connection portion (311) may cover at least a portion of the core hollow portion of the electrode assembly (20).

[0169] In one embodiment of the present invention, the electrode connection portion (313) 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).

[0170] In one embodiment of the present invention, referring to FIG. 12, the second collector plate (32) 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 the collector plate is not connected to the notched tab (27) of the second electrode (22).

[0171] In one embodiment of the present invention, referring to FIG. 13, the notched tab (27) of the second electrode (22) of the electrode assembly (20) may further include a second collector plate (32).

[0172] In one embodiment of the present invention, the second collector plate (32) may be made of copper. The second collector plate (32) may be manufactured by punching, trimming, piercing, and bending a metal sheet.

[0173] Referring to FIGS. 13 to 15, the second collector plate (32) may include a main body portion (320) connected to the notched tab (27) of the electrode assembly (20) and an outer ring-shaped can connection portion (324) disposed on a more distal side than the main body portion (320) and surrounding the edge of the second collector plate (32). The loop-shaped can connection portion (324) may be disposed radially apart from the main body portion (320).

[0174] The second collector plate (32) may include a bridge (325) whose centripetal side is connected to the main body (320) and whose centrifugal side is connected to the can connection part (324).

[0175] The main body (320) may include an inner ring (321) that defines a hole (322) corresponding to the core hollow portion of the electrode assembly (20) and is provided in a form that surrounds the core hollow portion, and an electrode tab connection portion (323) that extends radially from the inner ring portion (321). The main body (320) may be electrically connected to the notched tab (27) of the electrode assembly (20) by welding with a laser irradiated onto the electrode tab connection portion (323).

[0176] The electrode tab connection portion (323) may be joined to the notched tab (27) of the second electrode (22) of the electrode assembly (20) by laser welding or the like before the electrode assembly (20) is placed in the battery housing (10). The welding line of the laser may extend radially.

[0177] The above can connection portion (324) can be electrically connected to the main body portion (320) through the bridge (325) extending in a radial direction.

[0178] The above bridge (325) can be arranged alternately with the electrode tab connection portion (323) in the circumferential direction. The above bridge (325) can be connected to the inner ring portion (321).

[0179] In one embodiment of the present invention, referring to FIG. 3A, the second collector plate (32) may be coupled with the battery housing (20). Specifically, it may be coupled with the outer surface of the can connection portion (324) and the battery housing (10).

[0180] In one embodiment of the present invention, referring to FIG. 3a, the lead (40) may be axially spaced from the second collector plate (32) on the radially outer side. That is, the second collector plate (32) may not be in contact with the lead (40).

[0181]

[0182] In one embodiment of the present invention, as illustrated in FIGS. 16 and 17, the electrode assembly (20) can be accommodated in the battery housing (10) in a state where the first current collector (31) is aligned toward the bottom member (12) of the battery housing (10). At this time, an insulator (19) may be interposed between the first current collector (31) and the bottom member (12) of the battery housing (10) to electrically insulate the first current collector (31) from the bottom member (12).

[0183] In one embodiment of the present invention, the terminal connection portion (311) of the first 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 first current collector plate (31) and the first electrode terminal (13) can approach the back surface of the center of the terminal connection portion (311) of the first current collector plate (31) through the core hollow portion of the electrode assembly (20) from the other axial end of the electrode assembly (20), as illustrated in FIG. 17, and perform welding. Of course, in addition to this, the first current collector plate (31) and the first electrode terminal (13) can also be joined by a brazing or soldering method. That is, various methods can be applied to the first current collector plate (31) and the first electrode terminal (13) as long as they can be electrically connected and fixed to each other.

[0184]

[0185] Referring to FIGS. 18 and 19, a battery (1) having the lead described above applied can be accommodated in a housing (100) of a battery pack. The battery pack (P) may be configured using a battery module, which is an intermediate form of assembly, or the battery pack (P) may be configured directly without a battery module, as shown.

[0186] Since the battery (1) described above has a large volume in itself, there is no particular difficulty in implementing a battery pack (P) even without using an intermediate structure called a battery module. In addition, since the second electrode of the battery (1) is connected via a lead, the internal resistance can be reduced and the energy density can be increased.

[0187] Meanwhile, the battery pack (P) may be provided with a heat sink (101) on one side of the battery pack housing (100). At this time, if the outer diameter of the battery (1) is uniform without being affected by a welding bead (16a), etc., the contact area between the battery (1) and the heat sink (101) can be maximized, and the heat exchange efficiency of the battery (1) can be excellent due to the heat sink (101).

[0188] A battery pack (P) with such a high energy density can store the same amount of energy while reducing its volume and weight. Therefore, when a battery pack (P) equipped with such a battery (1) is installed in a vehicle (V) that uses electricity as its energy source, as illustrated in Fig. 19, the vehicle's mileage relative to its energy consumption can be further increased.

[0189]

[0190] 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 member, a bottom member connected to one axial end of the side wall member, and an opening provided at the other axial end of the side wall member; 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 opening; and A lid is included that is mounted on the outer surface of the axial end of the side wall member and covers the opening of the battery housing. A joint is formed so that the edge of the inner surface of the lead and the edge of the axial end of the side wall member are joined, A battery characterized in that the above-mentioned joint is recessed radially inward.

2. In claim 1, The above lead and the side wall member are joined by welding, The above joint is formed by a welding bead by the above welding, A battery characterized in that the above welding bead does not protrude radially outwardly from the battery housing.

3. In claim 1, A battery characterized in that the above-mentioned connecting portion is provided in a closed loop shape along the circumferential direction.

4. In claim 1, A battery characterized in that the radial diameter of the lead and the radial diameter of the axial other end of the battery housing are the same.

5. In claim 1, A battery characterized in that the axial other end of the side wall member has a first inclined portion on the radially outer side and a first flat portion connected to the first inclined portion and perpendicular to the side wall member.

6. In claim 5, A battery characterized in that the first inclined portion extends radially outward as it goes axially inward.

7. In claim 5, A battery characterized in that the angle (α) between the first inclined portion and the first flat portion is 100° or more and 170° or less.

8. In claim 5, A battery characterized in that the radial length of the first inclined portion is smaller than the radial length of the first flat portion.

9. In claim 1, A battery characterized in that the edge of the inner surface of the lead has a second inclined portion radially outward, and a second flat portion connected to the second inclined portion and perpendicular to the axial direction.

10. In claim 9, A battery characterized in that the second inclined portion extends radially outward as it goes axially outward.

11. In claim 9, A battery characterized in that the radial length of the second inclined portion is smaller than the radial length of the second flat portion.

12. In claim 9, A battery characterized in that the angle (β) between the second inclined portion and the second flat portion is 100° or more and 170° or less.

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

14. In claim 1, Further comprising a second collector plate connected to the second electrode, A battery characterized in that the second collector plate is coupled to the battery housing.

15. In claim 14, A battery characterized in that the lead is axially spaced from the second collector plate on the radially outer side.

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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