Battery cell, and battery pack and vehicle including same

Abstract

A battery cell according to one embodiment of the present invention may comprise: an electrode assembly in which a first electrode, a second electrode, and a separator interposed therebetween are wound around a winding axis; a can configured to accommodate the electrode assembly through an open end formed on one side; a lid covering the open end and having a filling port formed therein; a sealing member configured to seal the filling port, the sealing member including a sealing portion, which is configured to be inserted into at least a portion of the filling port, and a welded portion, which is configured to cover the filling port from above the lid and be welded to the lid; and a gasket surrounding at least a portion of the sealing member.

Description

Battery cells, battery packs containing the same, and vehicles

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

[0002] This application claims priority to Korean Patent Application No. 10-2024-0084041, filed on June 26, 2024, and all contents disclosed in the specification and drawings of the said application are incorporated by reference into this application.

[0003] This application claims priority to Korean Patent Application No. 10-2025-0076525, filed on June 11, 2025, and all contents disclosed in the specification and drawings of the said application are incorporated herein by reference.

[0004]

[0005] Cylindrical battery cells house jelly-roll-shaped electrode assemblies within a cylindrical metal can. They are more shock- and temperature-resistant than pouch-type batteries. Consequently, demand for metal can-shaped cells in vehicle battery packs is growing.

[0006] The process of manufacturing a battery cell using a cylindrical can includes deep drawing a metal sheet to form a circular bottom portion and a circular tubular side wall portion connected thereto, accommodating an electrode assembly therein, and then covering the open end of the side wall portion with a lead to finish the process.

[0007] The open end of the battery can is covered with a lead, and the lead and battery can are secured by crimping or seam welding.

[0008] Figure 1 is a drawing showing a method of fixing a lead and a battery can using a conventional crimping method.

[0009] Referring to Fig. 1, crimping is a method of physically pressing the edge of the lead (40) to the open end of the can (10) while interposing a sealing ring (91) to secure the lead (40). Since crimping is a physical fixing method that does not apply heat, it is possible to perform the operation while the electrolyte is poured into the can. Therefore, the crimping method has the advantage of being able to omit a separate pouring port structure and a structure for sealing it. However, crimping is structurally more complex than welding, and thus has limitations in securing the internal volume of the can that can accommodate the electrode assembly (20).

[0010] In contrast, seam welding involves welding the leading edge of the battery can's sidewall and the edge of the lead along the circumference, thereby simplifying the fixing structure and thus increasing the volume of the electrode assembly that can be accommodated within the battery can. Therefore, seam welding is more advantageous in securing electrical capacity relative to the same volume of the battery can.

[0011] However, when filling the battery can with electrolyte and covering the open end of the battery can with a lead and welding it, there is a possibility that the high temperature heat or plasma flame generated by welding may deteriorate or ignite when it comes into contact with electrolyte vapor in the air at a concentration above a certain level.

[0012] For example, if the can and lid are made of stainless steel, the surface temperature can rise to 1400 degrees Celsius, the melting point of stainless steel. This high temperature can cause the electrolyte to ignite.

[0013] Accordingly, when it is desired to fix the open end of the battery can by deep welding the lead, a method may be applied in which a battery can with a filler port provided at the bottom or a lead with a filler port provided is prepared, an electrode assembly is accommodated inside the battery can, the battery can and the lead are deep welded, an electrolyte is injected through the filler port provided at the bottom of the lead or the battery can, and after the injection is completed, the filler port is sealed.

[0014] For example, a sealing member, such as a metal ball, can be forcibly inserted into the injection port to seal and secure the injection port. This method involves forcibly inserting a metal ball with a diameter larger than the inner surface of the injection port into the injection port, and causing the surfaces of the inner surface of the injection port and the metal ball to be compressed together through elastic deformation, thereby forming a seal.

[0015] Aluminum balls have been used as metal balls to seal the filler port. Because aluminum balls can be sintered at low temperatures, forcibly inserting a slightly larger aluminum ball into the filler port deforms the aluminum, sealing the port. However, if the lead itself, where the filler port is formed, is the negative electrode of the battery electrode, aluminum balls cannot be used.

[0016] Meanwhile, if a steel ball is used instead of aluminum, a seal must be established between the rigid lead and the rigid ball. However, during the process of forcibly inserting the steel ball into the lead's inlet port, scratches parallel to the inlet direction occur on the inner surface of the inlet port and the surface of the steel ball. These scratches can cause problems, acting as channels through which gas within the battery cell can leak.

[0017] However, if the ball is pressed in with very strong force to eliminate even these channels, the lead itself will be deformed in the direction of pressing due to the force, which will not only cause a poor appearance of the lead, but there is also a risk that the deformed lead will come into contact with the electrode assembly inside the can, causing a short circuit.

[0018] Additionally, blind riveting can be used to physically seal the injection port. This method also requires a seal between the rigid rivet and the rigid lead. However, this method also causes scratches during the riveting process, leading to the same problem as described above.

[0019] Meanwhile, to reduce the possibility of gas leakage between the rigid lid and the rigid filler cap, one option is to cover the filler cap with a steel cap and then weld the gap between the cap and the filler cap to seal it. However, even with this method, the heat generated when welding the cap to the lid can cause the electrolyte inside the can to vaporize and release gas. This can lead to cracks or gas channels forming along the gas release path, and the high temperature, gas, and oxygen can cause a fire.

[0020] Therefore, a sealing method is required that does not cause electrolyte leakage, does not cause gas leakage due to electrolyte vaporization, and does not cause deformation of the lead.

[0021]

[0022] The present invention has been prepared to solve the problems described above, and the problem to be solved by the present invention is to provide a battery cell with an improved sealing structure of a liquid filler port and a method for manufacturing the same.

[0023] In addition, the present invention aims to provide a sealing structure of a liquid injection port with improved stability and a sealing method thereof, which has no possibility of welding defects or ignition at the welded portion due to electrolyte gas even when welding is applied to seal the liquid injection port.

[0024] In addition, the present invention aims to provide a sealing structure of a liquid injection port and a sealing method thereof that can minimize the number of parts and reduce assembly work.

[0025] In addition, another object of the present invention is to provide a method for manufacturing a battery cell using such a sealing method.

[0026] In addition, the present invention aims to provide a battery cell having a high energy density by excluding a beading crimping structure from the battery cell, and a vehicle equipped with a battery pack using the battery cell.

[0027] The technical objectives of the present invention are not limited to the aforementioned purposes. Other unmentioned objectives and advantages of the present invention can be understood through the following description and will be more clearly understood through the embodiments of the present invention. Furthermore, it will be readily apparent that the objectives and advantages of the present invention can be realized by the means and combinations thereof set forth in the claims.

[0028]

[0029] According to an embodiment of the present invention for solving the above-described problem, a battery cell may include: an electrode assembly in which a first electrode, a second electrode, and a separator interposed therebetween are wound around a winding axis; a can configured to receive the electrode assembly through an open end formed at one side thereof; a lid covering the open end and having a liquid inlet formed therein; a sealing member having a sealing portion configured to be inserted into at least a portion of the liquid inlet, and a welding portion configured to cover the liquid inlet on an upper side of the lid and to be welded to the lid, and configured to seal the liquid inlet; and a gasket surrounding at least a portion of the sealing member.

[0030] The above gasket may be in the shape of a ring surrounding at least a portion of a side surface of the sealing portion.

[0031] The above gasket may be positioned between the injection port and the sealing portion, and may be configured to seal between the injection port and the sealing portion.

[0032] The outer diameter of the above gasket may be larger than the inner diameter of the above injection port.

[0033] The above welding portion may extend outward in a radial direction perpendicular to the winding axis direction from the upper end of the sealing portion.

[0034] The diameter of the above welded portion may be larger than the inner diameter of the injection port.

[0035] The above lead may have a body portion; and a recessed portion surrounding the injection port and recessed downward in the direction of the winding axis from the body portion.

[0036] The welding part may be configured to be seated on the recessed part.

[0037] The above sealing member may have a groove portion recessed radially inwardly.

[0038] The above gasket may be seated in the above groove.

[0039] The maximum horizontal length of the above gasket may be greater than the horizontal length of the above groove.

[0040] The above can and lid may be heat bonded.

[0041] According to an embodiment of the present invention for solving the above-described other problems, a method for manufacturing a battery cell may include the steps of: covering an open end of a can with a lead while accommodating an electrode assembly in the can; thermally bonding an edge of the lead to the can; injecting an electrolyte into the can through a filler port of the lead; joining a gasket to a sealing portion of a sealing member; inserting the sealing member joined with the gasket into the filler port to seal between the filler port and the sealing member; and welding a welding portion of the sealing member and the lead.

[0042] A battery pack according to one embodiment of the present invention may include a battery cell according to one embodiment of the present invention.

[0043] A vehicle according to one embodiment of the present invention for solving the above-described problem may include a battery pack according to one embodiment of the present invention.

[0044]

[0045] According to one aspect of the present invention, a sealing structure of a liquid filler port and a sealing method thereof are provided, in which even when welding is applied for sealing a liquid filler port, there is no possibility of defects or ignition at the welded portion due to electrolyte gas, and the reliability of the liquid filler port sealing is improved.

[0046] According to one aspect of the present invention, by configuring the insertion of only one sealing member, which is a single joint component, into the injection port, the internal space of the cell can be relatively widened, and the width of the injection port can be formed wide, thereby improving the injection efficiency.

[0047] According to one aspect of the present invention, a temporary sealing force is secured by surrounding at least a portion of a side surface of a sealing member with a gasket to prevent external leakage of electrolyte vapor, and a high final sealing force is secured by thermally bonding a portion of a lead and an edge of the sealing member. Since thermal bonding can be performed while preventing external leakage of electrolyte vapor, for example, when laser welding is used as thermal bonding, there is an effect of preventing welding defects and ignition.

[0048] According to one aspect of the present invention, sealing can be achieved using two processes: press-fitting and thermal bonding, with a single, combined component. This reduces the number of components and assembly time.

[0049] A sealing member according to one aspect of the present invention is configured to be combined with a gasket to achieve double sealing.

[0050] However, the effects that can be obtained through the present invention are not limited to the effects described above, and other effects not mentioned can be clearly understood by those skilled in the art from the description of the invention described below.

[0051]

[0052] The following drawings attached to this specification illustrate preferred embodiments of the present invention and, together with the detailed description of the invention described below, serve to further understand the technical idea of ​​the present invention, and therefore, the present invention should not be interpreted as being limited to matters described in such drawings.

[0053] Figure 1 is a drawing showing a method of fixing a lead and a battery can using a conventional crimping method.

[0054] Figure 2 is a perspective view of a battery cell according to one embodiment of the present invention.

[0055] FIG. 3 is a perspective view showing a state before lamination of first electrodes, second electrodes, and separators for manufacturing an electrode assembly to be accommodated in a battery can according to one embodiment of the present invention.

[0056] Fig. 4 is a perspective view of an electrode assembly manufactured by winding the laminate of Fig. 3 into a jelly-roll shape.

[0057] FIG. 5 and FIG. 6 are perspective views showing a state in which a current collector plate is joined to each end of an electrode assembly according to one embodiment of the present invention.

[0058] Figure 7 is a cross-sectional view showing a process of accommodating an electrode assembly in a battery can according to one embodiment of the present invention.

[0059] Figure 8 is a cross-sectional view showing a state in which a can containing an electrode assembly according to one embodiment of the present invention is covered and sealed with a lead.

[0060] Fig. 9 is a cross-sectional view showing a state in which the injection port of a lead is sealed by a sealing member according to one embodiment of the present invention.

[0061] Fig. 10 is a cross-sectional view showing the appearance before a sealing member is inserted into the injection port of a lead according to one embodiment of the present invention.

[0062] Fig. 11 is a cross-sectional view showing the appearance after a sealing member is inserted into the injection port of a lead according to one embodiment of the present invention.

[0063] Fig. 12 is a perspective view showing the state before the sealing member and gasket are combined according to one embodiment of the present invention.

[0064] Fig. 13 is a cross-sectional view showing the appearance before a sealing member is inserted into the injection port of a lead according to another embodiment of the present invention.

[0065] Fig. 14 is a cross-sectional view showing the appearance after a sealing member is inserted into the injection port of a lead according to another embodiment of the present invention.

[0066] FIG. 15 is a cross-sectional view of a sealing member and a gasket according to another embodiment of the present invention.

[0067] Figure 16 is a flowchart of a method for manufacturing a battery cell to which the liquid cap sealing structure of the present invention is applied.

[0068] FIG. 17 is a drawing for explaining a battery pack according to one embodiment of the present invention.

[0069] FIG. 18 is a drawing for explaining a vehicle including the battery pack of FIG. 17.

[0070]

[0071] Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the attached drawings.

[0072] The present invention is not limited to the embodiments disclosed below, but can be implemented in various forms and with various modifications. However, these embodiments are provided to ensure that the disclosure of the present invention is complete and to fully inform those skilled in the art of the scope of the invention. Therefore, the present invention is not limited to the embodiments disclosed below, but should be understood to include all modifications, equivalents, and substitutes included within the technical spirit and scope of the present invention, as well as substitutions or additions of the components of one embodiment with those of another embodiment.

[0073] Furthermore, the present invention includes various embodiments. For each embodiment, redundant descriptions of substantially identical or similar components will be omitted, and the differences will be described.

[0074] The attached drawings are merely intended to facilitate understanding of the embodiments disclosed in this specification, and should not be construed as limiting the technical ideas disclosed in this specification, but should be understood to encompass all modifications, equivalents, and substitutes included within the spirit and technical scope of the present invention. In the drawings, the components may be expressed in exaggerated sizes or thicknesses for ease of understanding, but the scope of protection of the present invention should not be construed as being limited thereby.

[0075] The terminology used in this specification is only used to describe specific implementations or examples and is not intended to limit the present invention. In addition, the singular expression includes the plural expression unless the context clearly indicates otherwise. In the specification, terms such as "comprises" and "consists of" are intended to indicate the presence of a feature, number, step, operation, component, part, or combination thereof described in the specification. In other words, it should be understood that terms such as "comprises" and "consists of" in the specification do not exclude in advance the possibility of the presence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

[0076] While terms including ordinal numbers, such as "first" and "second," may be used to describe various components, these components are not limited by these terms. These terms are used solely to distinguish one component from another. Therefore, unless otherwise stated, a "first" component may also be a "second" component.

[0077] Throughout the specification, unless otherwise specifically stated, each element may be singular or plural.

[0078] As used herein, singular expressions include plural expressions unless the context clearly dictates otherwise. In this application, terms such as "consisting of" or "comprising" should not necessarily be construed to include all of the components or steps described in the specification, and should be construed to mean that some of the components or steps may not be included, or that additional components or steps may be included.

[0079] When a component is referred to as being "connected" or "connected" to another component, it should be understood that it may be directly connected or connected to that other component, but that there may be other components intervening. Conversely, when a component is referred to as being "directly connected" or "connected" to another component, it should be understood that there are no other components intervening.

[0080] When a component is referred to as being “above” or “below” another component, it should be understood that it is not only positioned directly above that other component, but that there may also be other components present in between.

[0081] Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. Terms defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant technology, and will not be interpreted in an idealized or overly formal sense unless explicitly defined herein.

[0082] Meanwhile, in this specification, terms indicating directions such as up, down, left, right, front, and back may be used, but these terms are only for convenience of explanation, and it is obvious to those skilled in the art that these terms may vary depending on the position, arrangement, rotation, and position of the object being targeted, or the position of the observer.

[0083] Throughout the 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.

[0084] In describing the embodiment, the winding axis direction refers to the direction in which the axis forming the winding center of the jelly-roll type electrode assembly extends, the radial direction refers to the direction approaching (centripetal) or moving away (centrifugal) from the axis, and the circumferential direction refers to the direction surrounding the axis.

[0085] Fig. 2 is a perspective view of a battery cell according to an embodiment of the present invention. Fig. 3 is a perspective view showing a state before lamination of first electrodes, second electrodes, and separators for manufacturing an electrode assembly to be accommodated in a battery can according to an embodiment of the present invention. Fig. 4 is a perspective view of an electrode assembly manufactured by winding the laminate of Fig. 3 in a jelly-roll shape. Figs. 5 and 6 are perspective views showing a state in which current collectors are respectively bonded to both ends of an electrode assembly according to an embodiment of the present invention. Fig. 7 is a cross-sectional view showing a process of accommodating an electrode assembly in a battery can. Fig. 8 is a cross-sectional view showing a state in which a can accommodating an electrode assembly according to an embodiment of the present invention is covered and sealed with a lid.

[0086] Hereinafter, with reference to FIGS. 2 to 8, an embodiment of a battery cell (1) to which the liquid cap sealing structure of the present invention is applied will be described in detail.

[0087] A battery cell (1) can be manufactured by embedding a cylindrical electrode assembly (20) inside a cylindrical battery can (10).

[0088] The battery cell (1) of the embodiment may include an electrode assembly (20), a current collector (31, 32) electrically connected to the electrode assembly (20), and a can (10) that accommodates the electrode assembly (20) and the current collector (31, 32).

[0089] The can (10) may include a side wall portion (11) extending in the direction of the winding axis between the first end and the second end, and a bottom portion (12) connected to the first end of the side wall portion (11) and extending in the radial direction. The second end of the side wall portion (11) in the direction of the winding axis may be open.

[0090] The open end of the above side wall portion (11) can be sealed by covering it with a lid (40) after accommodating the electrode assembly (20) in the can (10).

[0091] The above bottom portion (12) may have a disc shape with a hole formed in the center, and the side wall portion (11) may have a circular tube shape.

[0092] The above-mentioned bottom portion (12) and side wall portion (11) can be manufactured by forming a metal sheet with a nickel plated surface using a deep drawing process, and trimming the front end of the side wall portion (11) with a punch while holding it with a blank holder. Of course, the material of the can (10) is not limited to this.

[0093] A first electrode terminal (13) can be fitted into the hole. The first electrode terminal (13) can be fixed by riveting to the bottom portion (12) with a terminal gasket (14) interposed therebetween. The terminal gasket (14) is interposed between the first electrode terminal (13) and the bottom portion (12), thereby sealing the inside and outside of the can (10) to prevent leakage of the electrolyte and electrically insulating the first electrode terminal (13) and the bottom portion (12).

[0094] However, the method of connecting the first electrode terminal (13) and the bottom part (12) is not limited to this. For example, if the structure can seal between the first electrode terminal (13) and the bottom part (12) and electrically insulate the first electrode terminal (13) and the bottom part (12), various other fixing methods, such as a bolt-nut joint method, a glass seal method, or a chrome coating & PP-MAH thermal bonding method, can also be applied.

[0095] The first electrode terminal (13) above may have a first polarity, and the can (10) may have a second polarity. That is, the bottom (12) of the can (10), the side wall (11) connected thereto, and the lead (40) connected to the side wall (11), which will be described later, may all have a second polarity.

[0096] Accordingly, the battery cell (1) may have both the first electrode terminal (13) and the second electrode terminal (15) positioned at the winding axis end, i.e., the closed end, provided with the bottom portion (12). Then, the battery cell (1) 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 the upper portion of the battery cell (1).

[0097] In one example, 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.

[0098] An electrode assembly (20) is accommodated within the above can (10).

[0099] The electrode assembly (20) may be in the form of a jelly-roll in which a first electrode (21) and a second electrode (22) and a separator (28) interposed therebetween are wound in the direction of the winding axis. Specifically, the electrode assembly (20) may be manufactured as a cylindrical jelly-roll 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. 3, forming a laminate by sequentially stacking the first electrode (21), the separator (28), the second electrode (22), and the separator (28), and then winding this around the winding axis as illustrated in FIG. 4. The structure of the electrode assembly (20) is not limited by the embodiment, and may have a winding structure well known in the art.

[0100] The above first electrode (21) may be an anode, and the above second electrode (22) may be a cathode. Of course, the opposite may also be the case.

[0101] The above first electrode (21) and second electrode (22) are manufactured in the form of sheets. The electrode sheet is manufactured in the form of an active material layer (24) applied to the surface of a metal foil (23). The electrode sheet has 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 has a non-coated portion (26) region on one side in the width direction, and the negative electrode sheet has a non-coated portion (26) region on the other side in the width direction.

[0102] The non-conductive portion (26) is exposed or protrudes in the width direction of the laminate. The non-conductive portion (26) itself functions as an electrode tab.

[0103] In the above-mentioned blank portion (26), notches can be formed at a predetermined interval to form flag-shaped notching tabs (27).

[0104] In the embodiment, the notching tabs (27) are exemplified as having an equilateral trapezoidal shape. However, their shapes may be various, such as a semicircle, a semi-ellipse, a triangle, a rectangle, a parallelogram, etc.

[0105] In addition, in the embodiment, a form in which the notching tabs (27) arranged along the longitudinal direction have the same width is exemplified. However, the width of the notching tabs may be gradually or stepwise widened from the core side to the outer periphery side.

[0106] In addition, in the embodiment, a form in which the height of the notching tabs (27) gradually increases from the core side to the outer circumference side is exemplified. However, the height of these notching tabs may be implemented in a form in which they are constant or gradually decrease.

[0107] In addition, in the embodiment, a structure is exemplified in which a notching tab (27) is deleted in a predetermined section of the centrifugal end of the non-conductive portion (26) and a predetermined section of the centrifugal end. However, it is of course possible that the notching tab may not be deleted in the centrifugal end of the non-conductive portion, and that the notching tab may not be deleted in the centrifugal end of the non-conductive portion.

[0108] In the jelly-roll type electrode assembly (20), the notched tab (27) can be bent radially and flattened as shown in FIG. 4. The notched tab (27) can be bent radially inward or outward. In the embodiment, a structure in which the notched tab (27) is bent radially inward is exemplified.

[0109] The above-mentioned notched tabs (27) can be bent one by one during the process of forming a jelly-roll-shaped electrode assembly (20) by winding the laminate. Alternatively, the above-mentioned notched tabs (27) can be bent all at once after the laminate is wound to form a jelly-roll-shaped electrode assembly (20).

[0110] The notched tabs (27) of the first electrode (21) and the notched tabs (27) of the second electrode (22), which are folded and overlapped in the radial direction, can provide a plane substantially perpendicular to the winding axis direction at both ends of the electrode assembly (20) in the winding axis direction.

[0111] As shown in FIGS. 5 and 6, the first collector plate (31) and the second collector plate (32) can be joined to a substantially flat surface provided by bending the notched tabs (27) exposed at both ends in the winding axis direction of the electrode assembly (20).

[0112] In the embodiment, the first collector plate (31) is exemplified as a positive collector plate and the second collector plate (32) is exemplified as a negative collector plate. The first collector plate (31) may be made of aluminum, and the second collector plate (32) may be made of copper.

[0113] The above-mentioned collector plate (31, 32) can be manufactured by punching, trimming, piercing, and bending a metal sheet.

[0114] Referring to FIG. 5, the first collector plate (31) may include a first terminal connection portion (312) extending radially from the center, a ring portion (313) connecting the centrifugal edge of the first terminal connection portion (312) in a circumferential direction, and a first electrode connection portion (314) extending centripetally from the ring portion (313) but not connected to the first terminal connection portion (312). The center portion of the first terminal connection portion (312) may cover at least a portion of the winding center hole (H) of the electrode assembly (20).

[0115] The first electrode connection portion (314) is 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 can (10). The welding line of the laser may extend radially.

[0116] Referring to FIG. 6, the second collector plate (32) may include an inner ring (321) that defines a hole (322) corresponding to the winding center hole (H) of the electrode assembly (20) and is provided in a form surrounding the winding center hole (H), a second electrode connection part (323) extending radially from the inner ring (321), and a second terminal connection part (324) that is positioned on the centrifugal side of the second electrode connection part (323) and connected to the inner ring part (321). The second terminal connection part (324) may have an outer ring form that surrounds the edge of the second collector plate (32).

[0117] The second electrode 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 can (10). The welding line of the laser may extend radially.

[0118] However, the shape and structure of the first collector plate (31) and the second collector plate (32) are not limited to the above-described embodiment and may be designed in various ways. A structure in which the second collector plate (32) is omitted is also possible.

[0119] As illustrated in Fig. 7, the electrode assembly (20) can be accommodated in the can (10) in a state where the first collector plate (31) is aligned toward the bottom (12) of the can (10). At this time, an insulator (19) may be interposed between the first collector plate (31) and the bottom (12) of the can (10) to electrically insulate the first collector plate (31) from the bottom (12).

[0120] In a state where the electrode assembly (20) is accommodated inside the can (10), the notched tab (27) of the second electrode (22) and the second collector plate (32) can be arranged to face the open end of the side wall portion (11).

[0121] The first terminal connection portion (312) of the first collector plate (31) can be joined to the first electrode terminal (13) fixed to the can (10) by resistance welding, ultrasonic welding, laser welding, or the like. A welding device for welding the first collector plate (31) and the first electrode terminal (13) can approach the back surface of the center of the first terminal connection portion (312) of the first collector plate (31) through the open portion of the can (10), the hole (322) of the second collector plate (32), and the winding center hole (H) of the electrode assembly (20) to perform welding. Of course, the first collector plate (31) and the first electrode terminal (13) can also be joined by brazing or soldering. In other words, the first collector plate (31) and the first electrode terminal (13) can be electrically connected and fixed to each other in various ways. However, the present invention does not exclude a structure in which the positive electrode tab is directly electrically connected to the positive electrode terminal while omitting the positive electrode collector plate.

[0122] With the electrode assembly (20) housed in the can (10), the open end of the can (10) can be sealed and covered with a lid (40) as shown in FIG. 8.

[0123] The can (10) and the lead (40) can be thermally bonded. The periphery of the front end of the side wall portion (11) of the battery can (10) and the periphery of the edge of the lead (40) can be brought into contact and welded along the circumference. This can be defined as a seam welding method. Since the fixing structure is simple, the volume of the electrode assembly (20) that can be accommodated inside the can (10) can be secured accordingly. Therefore, the seam welding method is more advantageous in securing electric capacity per the same volume of the can (10).

[0124] Specifically, when it is desired to fix the open end of the can (10) and the lead (40) by deep welding, a method may be applied in which a can (10) having a liquid injection port provided at the bottom or a lead (40) having a liquid injection port is prepared, an electrode assembly (20) is accommodated inside the can (10), the can (10) and the lead (40) are deep welded, an electrolyte is injected through the liquid injection port provided at the bottom of the lead (40) or the can (10), and after the injection is completed, the liquid injection port is sealed with a plug or a sealing member (50).

[0125] The second terminal connection portion (324) of the second collector plate (32) and the second end of the side wall portion (11) can be joined by a method such as welding. The edges of the can (10) and the lid (40) can also be sealed and joined by a method such as welding. In one example, after the second collector plate (32) and the can (10) are joined, the lid (40) and the can (10) can be joined. In another example, after the second collector plate (32) and the lid (40) are joined, the lid (40) and the can (10) can be joined. In another example, the second collector plate (32), the can (10), and the lid (40) can be welded together.

[0126] The edge of the lead (40) can be electrically connected by being joined to the edge of the open end of the can (10). The inner surface of the can (10) or the lead (40) can be electrically connected to the second collector plate (32). Since the second collector plate (32) is joined to the notched tab (27) of the second electrode (22) of the electrode assembly (20) accommodated inside the can (10) of the battery cell (1), when the lead (40) is electrically connected to the second collector plate (32), the lead (40) can also be electrically connected to the notched tab (27) of the second electrode (22) of the electrode assembly (20). In a structure where the second collector plate (32) is omitted, the shape of the lead (40) can be changed so that the lead (40) can be directly electrically connected to the notched tab (27) of the second electrode (22) of the electrode assembly (20). After the can (10) is sealed with the lead (40), an electrolyte can be injected into the inside of the can (10) through the injection port (42) provided in the lead (40).

[0127] The lead (40) may be made of, for example, low-carbon steel. The lead (40) may be made of, for example, nickel-plated steel, cold-rolled steel (SPCC or SPCE), or stainless steel (SUS). The lead (40) may be manufactured, for example, by pressing and forming a metal plate.

[0128] Fig. 9 is a cross-sectional view showing a state in which a liquid injection port of a lid is sealed by a sealing member according to one embodiment of the present invention. Fig. 10 is a cross-sectional view showing a state before a sealing member is inserted into a liquid injection port of a lid according to one embodiment of the present invention. Fig. 11 is a cross-sectional view showing a state after a sealing member is inserted into a liquid injection port of a lid according to one embodiment of the present invention. Fig. 12 is a perspective view showing a state before a sealing member and a gasket are combined according to one embodiment of the present invention.

[0129] Referring to FIGS. 9 to 12, a battery cell (1) according to the present invention may include an electrode assembly (20), a can (10), a lead (40) in which a liquid injection port (42) is formed, a sealing member (50), and a gasket (60).

[0130] The injection port (42) may be provided in the center of the lead (40). The injection port (42) may, for example, serve as an electrolyte injection port.

[0131] The injection port (42) can be blocked by a sealing member (50). For example, the sealing member (50) can be inserted into the injection port (42).

[0132] The center of the injection port (42) may coincide with the center of the winding center hole (H) of the electrode assembly (20). That is, the injection port (42) of the lead (40) may be located above the winding center hole (H) of the electrode assembly (20) in the winding axis direction.

[0133] Meanwhile, the injection port (42) may be configured to discharge gases generated during a pre-charge process, which will be described later. That is, after a degassing process in which all gases generated during the pre-charge process are discharged through the injection port (42), the sealing member (50) may be configured to be bonded onto the injection port (42). Accordingly, the swelling phenomenon of the battery cell (1) can be reduced.

[0134] The sealing member (50) may be configured to seal the injection port (42). The sealing member (50) may mean, for example, a plug, a stopper, etc. that covers the injection port (42). The sealing member (50) may be configured to be inserted into the injection port (42). At least a portion of the sealing member (50) may penetrate the injection port (42). At least a portion of the sealing member (50) may be inserted into the interior of the injection port (42). The sealing member (50) is preferably a metal material that can be welded. The sealing member (50) may include at least one of low-carbon steel and copper (Cu).

[0135] By inserting the sealing member (50) into the liquid port (42) of the lead (40), the sealing property of the battery cell (1) can be secured. The sealing member (50) penetrates the liquid port (42) formed in the lead (40) to seal the outside and inside of the can (10), thereby preventing leakage of the electrolyte.

[0136] With this structure, the beading and crimping processes can be omitted, thereby achieving process simplification. Furthermore, the beading and crimping structure can prevent the phenomenon of dead space within the battery increasing in the winding axis direction of the electrode assembly (20), thereby lowering the energy density. In other words, with a structure such as the present invention, the energy density of the battery cell (1) can be improved.

[0137] According to one embodiment, referring to FIG. 10, the sealing member (50) may have a sealing portion (51) and a welding portion (52). The sealing member (50) may have a step formed between the welding portion (52) and the sealing portion (51).

[0138] The sealing portion (51) may be configured to be inserted into at least a portion of the injection port (42). For example, the diameter (R1) of the sealing portion (51) may be formed to be substantially the same as or smaller than the inner diameter (r) of the injection port (42). For example, the diameter (R1) of the sealing portion (51) may be formed to be smaller than the inner diameter (r) of the injection port (42). Accordingly, the sealing force of the injection port (42) can be adjusted by fitting the sealing portion (51) into the injection port (42). The sealing portion (51) may be fitted into the injection port (42) to primarily cover the injection port (42).

[0139] The sealing portion (51) may be located radially inward from the weld portion (52). A step may be formed between the sealing portion (51) and the weld portion (52). The sealing portion (51) may be a portion recessed downward from the weld portion (52) in the direction of the winding axis. The sealing portion (51) may have a shape that is concave downward from the weld portion (52) in the direction of the winding axis.

[0140] The sealing portion (51) can be combined with a gasket (60) that surrounds at least a portion of a side surface of the sealing portion (51). The sealing portion (51) combined with the gasket (60) can be inserted into the injection port (42). For example, the sealing portion (51) combined with the gasket (60) can be inserted into the injection port (42) in a force-fit manner.

[0141] According to the above-described embodiment of the present invention, the sealing member (50) has a sealing portion (51), so that it can be inserted into the injection port (42). In addition, the sealing portion (51) combined with the gasket (60) can be press-fitted into the injection port (42) and maintained in a fixed state even before welding. Therefore, the sealing member (50) can be prevented from being separated from the injection port (42) while being transported to the welding device. That is, the sealing portion (51) combined with the gasket (60) can be inserted into the injection port (42) before welding the lead (40) and the sealing member (50), so that primary sealing force can be secured first. Therefore, deterioration of the welding quality due to vaporization of the electrolyte can be prevented.

[0142] Referring to FIG. 11, the welded portion (52) may be configured to cover the injection port (42) on the upper side of the lead (40) and be mutually welded (W) with the lead (40). For example, resistance welding, ultrasonic welding, laser welding, or the like may be used for the welding (W). The welding (W) may be performed at the edge portion of the welded portion (52) facing the lead (40). For example, the welded portion (52) may be joined to the lead (40) using butt welding (W). At this time, for example, the melting point of the welded portion (52) may be approximately 100 degrees or more and 1400 degrees or less. That is, welding may be performed between the welded portion (52) and the lead (40) by applying heat of 100 degrees or more and 1400 degrees or less.

[0143] The above welding portion (52) may extend radially outwardly from the upper end of the sealing portion (51) perpendicular to the winding axis direction. The diameter (R2) of the welding portion (52) may be larger than the diameter (R1) of the sealing portion (51). For example, the diameter (R2) of the welding portion (52) may be approximately 1.2 times larger than the diameter (R1) of the sealing portion (51).

[0144] The diameter (R2) of the above welding portion (52) may be larger than the inner diameter (r) of the injection port (42). The sealing portion (51) and the welding portion (52) may both have a cylindrical shape with substantially the same center. The sealing portion (51) and the welding portion (52) may have a cylindrical shape with the same center and different outer diameters.

[0145] The weld (52) may be positioned to face the lead (40). The weld (52) may be positioned to overlap at least a portion of the lead (40) in the winding axis direction. Alternatively, the weld (52) may be positioned horizontally with at least a portion of the lead (40).

[0146] According to the above-described embodiment of the present invention, by welding the welded portion (52) and the lid (40), a secondary sealing force higher than the primary sealing force can be secured. Therefore, high airtightness can be secured. In addition, compared to a case where the sealing force is secured only by pressing, the pressing force of the sealing member (50) can be significantly reduced, thereby preventing permanent deformation of the lid (40) or the can (10) due to the pressing force.

[0147] Furthermore, according to the above-described embodiment of the present invention, since welding is performed after securing primary sealing strength, the phenomenon of electrolyte vapor leaking and ignition occurring during the welding process can be prevented. Therefore, events resulting from thermal runaway in a vehicle containing multiple battery cells, such as fire or explosion, can be prevented or delayed.

[0148] According to the above-described embodiment of the present invention, the inner surface of the welded portion (52) and the injection port (42) can be thermally bonded to secure a final sealing force higher than the temporary sealing force. Therefore, the final sealing force can be even greater than the temporary sealing force. At this time, the vaporized gas of the electrolyte generated by the welding heat can be prevented from coming into contact with the welded portion (52).

[0149] In this way, since the temporary sealing force is lower than the final sealing force, the pressing force of the sealing member (50) can be significantly reduced compared to the case where the sealing force is secured by pressing alone, and thus, permanent deformation of the lid (40) or can (10) due to the pressing force can be prevented.

[0150] In addition, since welding is performed after securing temporary sealing force, the phenomenon of electrolyte vapor leaking to the outside and ignition during the welding process can be prevented. Furthermore, the sealing part (51) and the welding part (52) configured to secure temporary sealing force are spaced apart in the winding axis direction, so that direct contact of electrolyte vapor with the welding area can be prevented. For example, the final sealing force that can be secured by welding is approximately 10 when the He leak standard leakage amount is -7 It can be less than atm.cc / s, which means that high confidentiality can be ensured.

[0151] A gasket (60) may surround at least a portion of the sealing member (50). The gasket (60) may be positioned between the liquid inlet (42) and the sealing portion (51), and may be configured to seal between the liquid inlet (42) and the sealing portion (51). The gasket (60) may be interposed between the sealing member (50) and the lid (40), thereby sealing the inside and the outside of the can (10) to prevent leakage of the electrolyte, and electrically insulating between the sealing member (50) and the lid (40). The gasket (60) may be in close contact between the sealing member (50) and the lid (40).

[0152] Referring to Fig. 12, the gasket (60) may be a ring shape that surrounds at least a portion of the side surface of the sealing portion (51). The gasket (60) may be coupled and fixed to the side surface of the sealing portion (51). The gasket (60) may be inserted into the injection port (42) and configured to be in circumferential contact with the inner surface of the injection port (42). A gasket hole (HG) may be formed at the center of the gasket (60). The sealing member (50) may be arranged to penetrate the gasket hole (HG). Therefore, it may be easy to seal the injection port (42) in the circumferential direction.

[0153] The above gasket (60) may include an elastic body. The gasket (60) may include, for example, a polymer material. The gasket (60) may include, for example, an O-ring. The gasket (60) may include, for example, a material with excellent elasticity and sealing properties, such as silicone or urethane.

[0154] The rubber material of the gasket (60) is a polymer compound with elastic properties that allows deformation caused by an external force to return to its original shape when the external force is removed, and thus the position can be fixed at the same time as it is combined with the sealing member (50). Since it is easy to combine the gasket (60) with the sealing member (50), manufacturing and assembly can be easy. In addition, when the gasket (60) is combined with the sealing member (50), it can be used and managed as a single component, making management easy.

[0155] The gasket (60) may be coupled and fixed to the side surface of the sealing member (50). For example, an adhesive material such as a waterproof tape or a waterproof bond may be included between the gasket (60) and the sealing member (50). When the gasket (60) is coupled and fixed to the side surface of the sealing member (51), the outer diameter (R3) of the gasket (60) may protrude radially outwardly more than the diameter (R1) of the sealing member (51). In this case, the gasket (60) may also be defined as a protrusion.

[0156] In addition, the outer diameter (R3) of the gasket (60) may protrude radially outwardly from the inner diameter (r) of the injection port (42). Therefore, when the sealing member (50) is inserted into the injection port (42) while the gasket (60) is fitted, it may be press-fitted. The gasket (60) may be positioned between the outer surface of the sealing member (50) and the inner surface of the injection port (42), and may be configured to be in close contact with the sealing member (50) and the injection port (42).

[0157] The sealing member (50) to which the gasket (60) is coupled can be forcibly fitted into the injection port (42). For example, the overlap dimension of the gasket (60) and the injection port (42) before press-fitting can be approximately 50 µm or more and 150 µm or less in the radial direction. For example, the overlap dimension of the gasket (60) and the injection port (42) can be approximately 70 µm or more and 150 µm or less in the radial direction.

[0158] According to the above embodiment of the present invention, the outer diameter (R3) of the gasket (60) is formed to be larger than the inner diameter (r) of the injection port (42), so that the sealing portion (51) of the sealing member (50) can be forcibly inserted into the injection port (42) using physical force, and the injected electrolyte can be prevented from flowing out of the injection port (42). In other words, by forcibly inserting the sealing member (50), the electrolyte vapor can be prevented from leaking out, and welding defects and ignition can be prevented during laser welding. The sealing portion (51) can be forcibly inserted into the injection port (42) to enable physical sealing.

[0159] That is, according to the above embodiment of the present invention, the sealing part (51) of the sealing member (50) can be first pressed into the injection port (42) before thermal bonding to secure a temporary sealing force to the extent that the sealing force can be secured against the pressure of the vaporized gas of the electrolyte generated by the welding heat generated when thermally bonding the lead (40) and the welding part (52). For example, the temporary sealing force secured by pressing the sealing member (50) is 10 based on the He leak. -5 10 inland -3It can be atm·cc / s.

[0160] Fig. 13 is a cross-sectional view showing the appearance before a sealing member is inserted into the liquid inlet of a lead according to another embodiment of the present invention. Fig. 14 is a cross-sectional view showing the appearance after a sealing member is inserted into the liquid inlet of a lead according to another embodiment of the present invention.

[0161] The lead (40) may have a step formed in the radial direction based on the periphery of the injection port (42). Specifically, the lead (40) may have a body portion (41) and a recess portion (43). The lead (40) may be divided into the body portion (41) and the recess portion (43) based on the step.

[0162] The body portion (41) may be configured to be coupled with the can (10). The edge of the body portion (41) may be in perpendicular contact with the open end of the can (10). The body portion (41) may be welded along the circumferential direction of the portion that contacts the open end of the can (10), which may be defined as a seam weld (as described above).

[0163] The recessed portion (43) may be a portion that surrounds the injection port (42) and is recessed downward in the direction of the winding axis from the body portion (41). The recessed portion (43) may be located radially inward from the body portion (41). The upper surface of the recessed portion (43) may be positioned lower than the upper surface of the body portion (41). That is, a step is formed between the recessed portion (43) and the body portion (41), and the step may be a ring shape extending in the circumferential direction with the injection port (42) as the center. The step may be formed by forging.

[0164] The thickness of the recessed portion (43) in the direction of the winding axis can be formed thinner than the thickness of the body portion (41) in the direction of the winding axis. A sealing member (50) can be mounted on the recessed portion (43). A welded portion (52) of the sealing member (50) can be mounted on the recessed portion (43).

[0165] According to the above embodiment of the present invention, a structure in which a welded portion (52) of a sealing member (50) can be secured can be formed by forging the area around the injection port (42).

[0166] In addition, according to the above-described embodiment of the present invention, the recessed portion (43), which is the portion where the sealing member (50) is coupled, is formed concavely toward the lower side toward the electrode assembly (20), so that even when the sealing member (50) is coupled, the overall height of the battery cell can be maintained constant. That is, when the sealing member (50) and the lead (40) are coupled, the sealing member (50) may not protrude upwards above the upper surface of the lead (40). A deviation in the overall height of the battery cell (1) may not occur. Therefore, the contact portion and / or contact area with a component (e.g., a heat sink) disposed on the upper side of the lead (40) is not limited by the sealing member (50) and can be maximized.

[0167] In addition, the lead (40) may further include a pipe portion (45). The pipe portion (45) may be a portion extending from an end of the recess portion (43) in a direction of the winding axis perpendicular to the recess portion (43). For example, a funnel-shaped pipe portion (45) may be formed by punching a micro-hole in the recess portion (43) and then pushing it into a mold in the shape of a rod (determining the inner diameter of the injection port), thereby forming the injection port (42). The injection port (42) may be defined by the pipe portion (45) extending from the center of the lead (40) in the direction of the winding axis. In other words, the inner surface of the pipe portion (45) may be defined as the injection port (42). The inner surface of the injection port (42) may be understood to refer to the inner surface of the pipe portion (45). For example, the penetration cross-section of the injection port (42) defined by the inner surface of the above-mentioned pipe (45) may be circular.

[0168] According to the above-described embodiment of the present invention, even if the gasket (60) is positioned somewhat below the sealing portion (51), the sealing force between the lid (40) and the sealing member (50) can be maintained. That is, the extension length of the pipe portion (45) in the winding axis direction can be designed by the length of the sealing member (50) in the winding axis direction. For example, the lower surface of the pipe portion (45) can be positioned at substantially the same height as the lower surface of the sealing member (50).

[0169] FIG. 15 is a cross-sectional view of a sealing member and a gasket according to another embodiment of the present invention.

[0170] The sealing member (50) may have a groove (53) that is recessed radially inward. The groove (53) may be a receiving area for the gasket (60) so that the gasket (60) is coupled at a designated location.

[0171] A groove (53) may be provided at a location where a gasket (60) is placed. The groove (53) may be provided in a sealing portion (51) of a sealing member (50). The groove (53) is formed along the outer surface of the sealing portion (51) and may act as a mechanical reference surface for stable position fixation of the gasket (60).

[0172] The gasket (60) can be seated in the groove (53). At least a portion of the gasket (60) can be inserted into the groove (53). The maximum horizontal length (d1) of the gasket (60) can be designed to be greater than the horizontal length (d2) of the groove (53). Therefore, when the sealing member (50) to which the gasket (60) is coupled is inserted into the injection port (42), the gasket (60) can be compressed to strengthen the sealing force.

[0173] According to the above-described embodiment of the present invention, at least a portion of the gasket (60) is inserted into the groove (53) and fixed in position, thereby preventing displacement due to vibration, thermal expansion, or external force that may occur during assembly or long-term use. Accordingly, the sealing performance of the gasket (60) can be significantly improved.

[0174] Figure 16 is a flowchart illustrating a method for manufacturing a battery cell to which the liquid cap sealing structure of the present invention is applied. Hereinafter, a method for manufacturing a battery cell according to an embodiment of the present invention will be described with reference to Figure 16. For convenience of explanation, the description may be made with reference to the drawings of Figures 1 to 15.

[0175] First, an electrode assembly (20) can be prepared (S1) including a can (10) in which a first electrode terminal (13) is fixed in an insulating seal on a bottom portion (12), and a first collector plate (31) and a second collector plate (32) welded to the first electrode and the second electrode at both ends, respectively.

[0176] Next, a step of covering the open end with the lead (40) while the electrode assembly (20) is accommodated in the can (10) may be included (S2).

[0177] The electrode assembly (20) can be accommodated in the can (10) in a state where the first collector plate (31) is aligned so as to face the bottom (12) of the can (10). At this time, an insulator (19) can be interposed between the first collector plate (31) and the bottom (12) of the can (10) to electrically insulate the first collector plate (31) from the bottom (12).

[0178] A step of bonding the edge of the lead (40) to the can (10) may be included (S3). The lead (40) and the can (10) may be thermally bonded.

[0179] Before joining the edge of the lead (40) to the can (10), the first collector plate (31) can be thermally joined to the first electrode terminal (13). In addition, the open end of the can (10) can be sealed by covering it with the lead (40), and the second collector plate (32) can be electrically connected to the can (10) and the lead (40), which are the second electrode terminals (15), by joining the second collector plate (32) to the can (10) and / or the lead (40), and the lead (40) and the can (10) can be thermally joined.

[0180] The first collector plate (31) can be joined to the first electrode terminal (13) fixed to the can (10) by resistance welding, ultrasonic welding, laser welding, or the like. A welding device for welding the first collector plate (31) and the first electrode terminal (13) can approach the back surface of the center of the first terminal connection portion (312) of the first collector plate (31) through the open portion of the can (10), the hole (322) of the second collector plate (32), and the winding center hole (H) of the electrode assembly (20) to perform welding. Of course, in addition to this, the first collector plate (31) and the first electrode terminal (13) can also be joined by brazing or soldering. In other words, various methods can be applied to the first collector plate (31) and the first electrode terminal (13) as long as they can be electrically connected and fixed to each other.

[0181] The second collector plate (32) and the second end of the side wall portion (11) can be joined by a method such as welding. The edges of the can (10) and the lid (40) can also be sealed by a method such as welding. In one example, after the second collector plate (32) and the can (10) are joined, the lid (40) and the can (10) can be joined. In another example, after the second collector plate (32) and the lid (40) are joined, the lid (40) and the can (10) can be joined. In another example, the second collector plate (32), the can (10), and the lid (40) can be welded together.

[0182] The edge of the lead (40) can be electrically connected by being joined to the edge of the open end of the can (10). The inner surface of the can (10) or the lead (40) can be electrically connected to the second collector plate (32). Since the second collector plate (32) is joined to the notched tab (27) of the second electrode (22) of the electrode assembly (20) accommodated inside the can (10) of the battery cell (1), when the lead (40) is electrically connected to the second collector plate (32), the lead (40) can also be electrically connected to the notched tab (27) of the second electrode (22) of the electrode assembly (20). In a structure where the second collector plate (32) is omitted, the shape of the lead (40) can be changed so that the lead (40) can be directly electrically connected to the notched tab (27) of the second electrode (22) of the electrode assembly (20).

[0183] Next, a step of injecting an electrolyte into the battery can (10) through the injection port (42) of the lead (40) may be included (S4).

[0184] Next, a step of joining the gasket (60) to the sealing portion (51) of the sealing member (50) may be included (S5).

[0185] The gasket (60) may surround at least a portion of the sealing member (50). The gasket (60) may have a ring shape that surrounds at least a portion of the side surface of the sealing portion (51). The gasket (60) may be coupled and fixed to the side surface of the sealing portion (51). A gasket hole (HG) may be formed at the center of the gasket (60). The sealing member (50) may be arranged to penetrate the gasket hole (HG). Therefore, it may be easy to seal the injection port (42) in the circumferential direction.

[0186] The above gasket (60) may include an elastic body. The gasket (60) may include, for example, a polymer material. The gasket (60) may include, for example, an O-ring. The gasket (60) may include, for example, a material with excellent elasticity and sealing properties, such as silicone or urethane.

[0187] The rubber material of the gasket (60) is a polymer compound with elastic properties that allows deformation caused by an external force to return to its original shape when the external force is removed, and thus the position can be fixed at the same time as it is combined with the sealing member (50). Since it is easy to combine the gasket (60) with the sealing member (50), manufacturing and assembly can be easy. In addition, when the gasket (60) is combined with the sealing member (50), it can be used and managed as a single component, making management easy.

[0188] The gasket (60) can be bonded and fixed to the side of the sealing member (50). For example, an adhesive material such as a waterproof tape or waterproof bond may be included between the gasket (60) and the sealing member (50).

[0189] Next, after the electrolyte is injected, a sealing member (50) combined with the gasket (60) can be inserted into the injection port (42) (S6). As the gasket (60) is pressed between the injection port (42) and the sealing member (50), the space between the injection port (42) and the sealing member (50) can be sealed.

[0190] Specifically, the sealing portion (51) of the sealing member (50) can be inserted into the injection port (42). Here, the sealing member (50) may be in a state in which a gasket (60) is coupled. For example, the sealing portion (51) coupled with the gasket (60) can be inserted into the injection port (42) in a force-fit manner. According to the above embodiment of the present invention, the sealing portion (51) of the sealing member (50) can be forcibly inserted into the injection port (42), and the electrolyte formed inside can be prevented from flowing out of the injection port (42). In other words, by forcibly inserting the sealing member (50), the electrolyte vapor can be prevented from leaking out, and welding defects and ignition can be prevented during laser welding. The sealing portion (51) can be forcibly inserted into the injection port (42) to enable physical sealing.

[0191] In addition, according to the above embodiment of the present invention, the sealing part (51) of the sealing member (50) can be first pressed into the injection port (42) before thermal bonding to secure a temporary sealing force to the extent that the sealing force can be secured against the pressure of the vaporized gas of the electrolyte generated by the welding heat generated when thermally bonding the lead (40) and the welding part (52). For example, the temporary sealing force secured by pressing the sealing member (50) is 10 based on the He leak. -5 10 inland -3 It can be atm·cc / s.

[0192] That is, the sealing member (50) according to one aspect of the present invention is configured to be combined with a gasket (60) to implement double sealing.

[0193] In addition, when a conventional rigid body such as a ball or rivet is pressed with a very strong force into the injection port (42), a problem of scratches occurring has occurred. In contrast, according to the above-described embodiment of the present invention, a gasket (60) made of an elastic material is placed between the rigid sealing member (50) and the injection port (42), so that scratches may not occur inside the injection port (42) or the sealing member (50).

[0194] Finally, a step of welding the sealing member (50) and the lead (40) may be included (S7).

[0195] The above sealing finish can be achieved by first securing a temporary sealing force by pressing the sealing member (50) into the injection port (42), and then sealing the welded portion (52) of the sealing member (50) and the lead (40) by welding to secure the final sealing force.

[0196] For example, the weld (52) and the lead (40) of the sealing member (50) can be laser welded. Laser welding can be defined as a process of melting and joining metal using a laser beam with high energy density.

[0197] The ultimate sealing strength can be greater than the temporary sealing strength. For example, the ultimate sealing strength that can be achieved by welding is approximately 10 times the He leak rate. -7 It can be less than atm.cc / s, which means that high confidentiality can be ensured.

[0198] According to the above-described embodiment of the present invention, since welding is performed after securing temporary sealing force, the phenomenon of gas channels being formed or cracks occurring during the welding process can be prevented, thereby preventing defects in the welded portion (52).

[0199] In addition, according to the above-described embodiment of the present invention, since welding is performed after securing temporary sealing force, the phenomenon of electrolyte vapor leaking to the outside and ignition during the welding process can be prevented.

[0200] Fig. 17 is a drawing for explaining a battery pack according to one embodiment of the present invention. Fig. 18 is a drawing for explaining a vehicle including the battery pack of Fig. 17.

[0201] Referring to FIG. 17, a battery pack (P) according to the present invention may include at least one battery cell (1) according to the present invention described above. In addition, the battery pack (P) according to the present invention may include a pack housing (2) capable of accommodating the at least one battery cell (1). The battery pack (P) may be configured using a battery module, which is an intermediate form of assembly, or may be configured directly without a battery module, as illustrated. Since the battery cell (1) itself has a large volume, there may be no particular difficulty in implementing the battery pack (P) even without using an intermediate structure called a battery module.

[0202] In addition, the battery pack (P) may further include various other components in addition to the battery cells (1), such as components of the battery pack (P) known at the time of application of the present invention, such as a BMS, a relay, a current sensor, etc.

[0203] A battery pack (P) may include a plurality of battery cells (1). The battery cells (1) may be arranged in a predetermined number of rows, and may be arranged such that the first electrode terminal (13) and the second electrode terminal (15) of each battery cell (1) are both positioned on the upper side. Therefore, when electrically connecting the plurality of battery cells (1), both the positive and negative electrodes can be connected in one direction, thereby simplifying the electrical connection structure. This increases the number of battery cells (1) that can be mounted in the same space, thereby improving energy density and facilitating electrical wiring work. Therefore, the space efficiency is good, and the electrical wiring efficiency is high, which significantly improves workability during the assembly process of the electric vehicle, as well as during the assembly and maintenance of the battery pack (P). In addition, as described above, each battery cell (1) may have a higher energy density than before. A battery pack (P) with such a high energy density can store the same amount of energy while reducing its volume and weight.

[0204] Therefore, if a battery pack (P) to which such a battery cell (1) is applied is mounted on a vehicle such as an automobile (M) that uses electricity as an energy source as shown in Fig. 18, the mileage of the vehicle can be further increased in proportion to the energy consumed.

[0205] Referring to FIG. 18, a vehicle (M) according to the present invention may include at least one battery pack (P) according to the present invention.

[0206] The battery cell (1) according to the present invention can be applied to automobiles such as electric vehicles or hybrid vehicles. That is, the automobile (M) according to the present invention can include the battery cell (1) according to the present invention or the battery pack (P) according to the present invention. In addition, the automobile (M) according to the present invention can further include various other components included in the automobile in addition to the battery cell (1) or the battery pack (P). For example, the automobile (M) according to the present invention can further include a body, a motor, a control device such as an ECU (electronic control unit), etc. in addition to the battery cell (1) according to the present invention. The automobile (M) includes a four-wheeled automobile and a two-wheeled automobile. The automobile (M) can operate by receiving power from the battery pack (P) according to one embodiment of the present invention.

[0207] Although the present invention has been described above with reference to limited embodiments and drawings, the present invention is not limited thereto, and it is obvious that various modifications and variations are possible within the scope of the technical idea of ​​the present invention and the equivalent scope of the claims to be described below by a person having ordinary skill in the art to which the present invention pertains.

Claims

1. An electrode assembly in which a first electrode, a second electrode, and a separator interposed therebetween are wound around a winding axis; A can configured to receive the electrode assembly through an open end formed on one side; A lead covering the above open end and having a liquid hole formed therein; A sealing member configured to seal the injection port, comprising a sealing portion configured to be inserted into at least a portion of the injection port, and a welding portion configured to cover the injection port on the upper side of the lead and to be mutually welded to the lead; and A battery cell comprising a gasket surrounding at least a portion of the sealing member.

2. In paragraph 1, A battery cell characterized in that the gasket has a ring shape surrounding at least a portion of a side surface of the sealing portion.

3. In paragraph 1, A battery cell characterized in that the gasket is positioned between the liquid port and the sealing portion and is configured to seal between the liquid port and the sealing portion.

4. In paragraph 1, A battery cell characterized in that the outer diameter of the gasket is larger than the inner diameter of the injection port.

5. In paragraph 1, A battery cell characterized in that the welding portion extends outward in a radial direction perpendicular to the winding axis direction from the upper end of the sealing portion.

6. In paragraph 1, A battery cell characterized in that the diameter of the welded portion is larger than the inner diameter of the injection port.

7. In paragraph 1, The above lead is a body part; and A battery cell characterized by having a recessed portion that surrounds the above-mentioned injection port and is recessed downward in the direction of the winding axis compared to the above-mentioned body portion.

8. In paragraph 7, A battery cell characterized in that the welding part is configured to be seated on the recessed part.

9. In paragraph 1, A battery cell characterized in that the sealing member has a groove portion recessed radially inwardly.

10. In paragraph 9, A battery cell characterized in that the gasket is seated in the groove.

11. In paragraph 9, A battery cell characterized in that the maximum horizontal length of the gasket is greater than the horizontal length of the groove.

12. In paragraph 1, A battery cell characterized in that the can and the lead are thermally bonded.

13. A method for manufacturing a battery cell according to any one of claims 1 to 12, A step of covering the open end of the can with a lead while housing the electrode assembly in the can; A step of thermally bonding the edge of the lead to the can; A step of injecting electrolyte into the can through the injection port of the lead; A step of joining a gasket to a sealing portion of a sealing member; A step of sealing between the injection port and the sealing member by inserting the sealing member combined with the gasket into the injection port; and A method for manufacturing a battery cell, comprising: a step of welding the lead to the welding portion of the sealing member; 14. A battery pack including a battery cell according to any one of claims 1 to 12.

15. A vehicle equipped with a battery pack as per Article 14.

Images