Electrolyte injection O-ring and manufacturing method for cylindrical battery using the same

Abstract

The present invention discloses an electrolyte injection O-ring and a method for manufacturing a cylindrical battery using the same. The electrolyte injection O-ring according to the present invention may include a main body portion having open upper and lower ends and defining a cavity along a central axis, and an expanded diameter portion extending from a lower portion of the main body portion in a centrifugal direction and along the central axis. The expanded diameter portion may include an outer circumferential surface surrounding the central axis, and when pressure is applied in the axial direction, the expanded diameter portion may be elastically deformed, thereby increasing the diameter of the outer circumferential surface in the centrifugal direction.

Description

[Technical Field]

[0001] The present invention relates to an electrolyte injection O-ring and a method for manufacturing a cylindrical battery using the same, and more particularly to an electrolyte injection O-ring that can prevent electrolyte from remaining in a beading portion and a method for manufacturing a cylindrical battery using the same.

[0002] This application claims priority based on Korean Patent Application No. 10-2022-0183770, filed on December 23, 2022, the entire contents of which are incorporated herein by reference in their entirety in the specification and drawings thereof. [Background technology]

[0003] The cylindrical battery includes an electrode assembly wound in a jelly roll shape, a cylindrical can containing the electrode assembly and having one open end, and a cap assembly sealing the top of the cylindrical can.

[0004] A beading portion is formed near the open end of the cylindrical can as a support structure for mounting the cap assembly. The beading portion has a groove structure recessed to a certain depth along the outer periphery of the cylindrical can toward the central axis of the cylindrical can.

[0005] The end of the cap assembly is mounted on the upper surface of the beading portion. A gasket is interposed between the upper surface of the beading portion and the end of the cap assembly. The open end of the cylindrical can is crimped toward the central axis to pressurize the end of the cap assembly together with the gasket. This causes the open portion of the cylindrical can to be airtightly sealed by the cap assembly.

[0006] The electrolyte is injected before the cap assembly is sealed, and the electrode assembly is inserted into the cylindrical can where the electrolyte is injected. An electrolyte injection O-ring is attached to the top of the cylindrical can to prevent the electrolyte from leaking out during the electrolyte injection process.

[0007] FIG. 1 is a cross-sectional view showing a schematic structure of a conventional cylindrical can 10 to which an electrolyte injection O-ring 20 is attached.

[0008] 1, electrolyte injection O-ring 20 is in close contact with the upper end of cylindrical can 10. The top of electrolyte injection O-ring 20 is in close contact with electrolyte injector 30. When electrolyte E is injected from electrolyte injector 30, the electrolyte E falls toward electrode assembly JR by gravity and gradually seeps into the electrode assembly JR.

[0009] Some of the droplets of the electrolyte solution E discharged from the electrolyte solution injector 30 may scatter toward the beading portion 40. Furthermore, if the amount of electrolyte solution E discharged is relatively greater than the amount of electrolyte solution E that soaks into the electrode assembly JR, the liquid level of the electrolyte solution E may rise to above the beading portion 40.

[0010] A step A may be formed at the corner where the beading portion 40 meets the inner wall of the cylindrical can 10. The step A may be formed unintentionally in the process of applying pressure to the upper end of the cylindrical can 10 in the direction of gravity in order to make the upper surface 40a of the beading portion 40 substantially parallel to the bottom surface of the cylindrical can 10.

[0011] For reference, when the upper surface 40 a of the beading portion 40 is substantially parallel to the bottom surface of the cylindrical can 10 , the end of the cap assembly can be stably mounted on the upper surface of the beading portion 40 .

[0012] The step A is a kind of groove structure formed on the outer side of the upper surface 40a of the beading portion 40. The groove structure may extend in the circumferential direction in the form of a closed loop.

[0013] The scattering of the electrolyte E and the rise in the liquid level of the electrolyte E cause the electrolyte E' to remain on the step A of the beading portion 40 even after the electrolyte injection is completed.

[0014] The electrolyte E' remaining in the step A may leak out of the cylindrical can 10 during the crimping process, in which the cap assembly together with the gasket is installed on the upper surface 40a of the beading portion 40 and the upper end of the cylindrical can 10 is bent and fixed, or during the sizing process, in which pressure is applied to the crimped portion in the direction of gravity to adjust the height of the cylindrical can 10 to the designed height.

[0015] The leaked electrolyte E' may corrode the outer surface of the cylindrical can 10. Furthermore, if the leaked electrolyte E' penetrates the welded portion of the bus bar, it corrodes the welded portion and increases the resistance of the welded portion. Furthermore, if the corrosion of the welded portion is severe, it may cause the bus bar to break. Summary of the Invention [Problem to be solved by the invention]

[0016] The present invention was conceived in light of the background of the above-mentioned conventional technology, and aims to provide an electrolyte injection O-ring having an improved structure that prevents electrolyte from remaining in the stepped portion of the beading portion even after the electrolyte injection process is completed.

[0017] Another object of the present invention is to provide a method for manufacturing a cylindrical battery using an electrolyte injection O-ring having an improved structure. [Means for solving the problem]

[0018] To achieve the above object, the electrolyte injection O-ring according to the present invention may include a main body portion having open upper and lower ends and defining a cavity along a central axis, and an expanded diameter portion extending from a lower portion of the main body portion in the centrifugal direction and along the central axis direction.

[0019] The enlarged diameter portion includes an outer peripheral surface surrounding the central axis, and when pressure is applied in the direction of the central axis, the enlarged diameter portion is elastically deformed, thereby causing the diameter of the outer peripheral surface to increase in the centrifugal direction.

[0020] The expanded diameter portion may have a first bottom surface extending from a lower end of the outer circumferential surface toward the central axis so as to be substantially perpendicular to the central axis.

[0021] The expanded diameter portion may include an inclined surface extending obliquely from an outer peripheral surface of the main body portion along the centrifugal direction and the central axis direction.

[0022] The expanded diameter portion may include a first upper surface that connects the inclined surface and the outer circumferential surface and is substantially perpendicular to the central axis.

[0023] The main body may have a second top surface and a second bottom surface at an upper end and a lower end, respectively.

[0024] The main body portion may have, on an inner circumferential surface facing the cavity, a groove recessed in a centrifugal direction and extending along a circumferential direction.

[0025] The first bottom surface may be located more outward than the second bottom surface in the centrifugal direction.

[0026] The expanded diameter portion may include a curved surface portion connecting the first bottom surface and the second bottom surface.

[0027] The outer peripheral surface may include a centrifugal and circumferentially extending projection.

[0028] The protrusion may circumscribe the central axis.

[0029] To achieve the above object, the present invention provides a cylindrical battery manufacturing method, which comprises: (a) forming a cylindrical battery having an open end at one end and a closed end at the other end; (b) inserting a jelly-roll-type electrode assembly into the cylindrical can; (c) forming a groove-shaped beading portion at a point spaced a predetermined distance from the open end of the cylindrical can by pressing the beading portion toward the central axis of the cylindrical can; (d) attaching the electrolyte injection O-ring to the inside of the open end of the cylindrical can such that the bottom surface of the enlarged diameter portion of the electrolyte injection O-ring faces the beading portion and the outer circumferential surface of the enlarged diameter portion faces the inner circumferential surface of the cylindrical can near the open end; (e) connecting an electrolyte injector to an upper portion of a body portion of the electrolyte injection O-ring and pressing the electrolyte injection O-ring toward the electrode assembly; and (f) injecting electrolyte into the cavity of the body portion using the electrolyte injector.

[0030] The groove shape of the beading portion may include upper and lower surfaces facing each other along the central axis direction, and a step may be formed in a region where the upper surface of the beading portion contacts the inner circumferential surface of the cylindrical can between the beading portion and the open end.

[0031] In step (e), the enlarged diameter portion is elastically deformed, so that the outer diameter of the outer peripheral surface of the enlarged diameter portion may increase in the centrifugal direction.

[0032] In step (e), the outer circumferential surface of the enlarged diameter portion may be in close contact with the inner circumferential surface of the cylindrical can between the beading portion and the open end.

[0033] In step (e), the protrusions provided on the outer peripheral surface of the enlarged diameter portion may be pressed against the inner peripheral surface of the cylindrical can and may be elastically deformed.

[0034] The method for manufacturing a cylindrical battery according to the present invention includes the steps of: forming an opening at a closed end of the cylindrical can, and attaching a rivet terminal between the opening and the closed end and interposing a gasket between the opening and the closed end; forming a stack having a separator interposed between a positive electrode and a negative electrode, each having an uncoated portion at an end of a long side; and winding the stack in the long side direction to manufacture a jelly roll-type electrode assembly, such that the uncoated portion of the positive electrode and the uncoated portion of the negative electrode are exposed to the outside of the separator at one end and the other end of the electrode assembly, respectively; and folding the uncoated portion of the positive electrode toward a core of the electrode assembly to form a first folding. forming a first bent surface region and coupling a positive current collector to the first bent surface region; folding an uncoated portion of the negative electrode toward a core of the electrode assembly to form a second bent surface region and coupling a negative current collector to the second bent surface region; inserting the electrode assembly into the cylindrical can such that an insulator is interposed between the positive current collector and the closed end and an end of the negative current collector is positioned above the beading portion; electrically connecting the positive current collector and the rivet terminal; and electrically connecting the end of the negative current collector to the upper surface of the beading portion.

[0035] The negative electrode current collector plate may include a support portion disposed around the core, a plurality of non-coated portion joining portions extending from the support portion and joining to the second folded surface region, and a plurality of beading portion connecting portions extending from the support portion toward the beading portion along the centrifugal direction and the winding axis direction and electrically connecting to an upper portion of the beading portion.

[0036] The bottom surface of the enlarged diameter portion can be in close contact with the plurality of beading portion connection portions and the upper surface of the beading portion exposed between the circumferentially adjacent beading portion connection portions at the same time.

[0037] The method for manufacturing a cylindrical battery according to the present invention may further include, before performing step (e), interposing a coupling O-ring between the electrolyte injection O-ring and the electrolyte injector. [Effects of the Invention]

[0038] According to the present invention, when the electrolyte injection O-ring is pressed in the direction of gravity from above by the electrolyte injector, it hermetically adheres to the upper surface of the beading portion and the stepped portion outside it, thereby fundamentally preventing the phenomenon of electrolyte remaining on the upper surface of the beading portion, especially on the stepped portion, even after the electrolyte injection process is completed.

[0039] The following drawings attached to this specification illustrate preferred embodiments of the present invention and, together with the detailed description of the invention, serve to further understand the technical concept of the present invention, so the present invention should not be interpreted as being limited to the matters described in the drawings. [Brief explanation of the drawings]

[0040] [Figure 1] 1 is a cross-sectional view showing a schematic structure in which an electrolyte injection O-ring is attached to the top of a cylindrical can in the prior art. [Figure 2] 1 is a perspective cross-sectional view showing the structure of an electrolyte injection O-ring according to an embodiment of the present invention. [Figure 3] 1 is a cross-sectional view showing the structure of an electrolyte injection O-ring according to an embodiment of the present invention. [Figure 4] 1A to 1C are process diagrams illustrating a method for manufacturing a cylindrical battery according to an embodiment of the present invention. [Figure 5] 1A to 1C are process diagrams illustrating a method for manufacturing a cylindrical battery according to a preferred embodiment of the present invention. [Figure 6] 1 is a process diagram showing an embodiment of the present invention applied to a cylindrical battery of form factor 4680. [Figure 7] FIG. 2 is a plan view showing the structure of a positive electrode current collector plate according to an embodiment of the present invention. [Figure 8] 1 is a perspective view showing the structure of a negative electrode current collector plate according to an embodiment of the present invention; DETAILED DESCRIPTION OF THE INVENTION

[0041] Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings. Prior to this, the terms and words used in this specification and claims should not be construed as being limited to their ordinary or dictionary meanings, but should be construed as meanings and concepts corresponding to the technical concept of the present invention, in accordance with the principle that the inventor himself can appropriately define the concept of terms in order to best explain the invention. Therefore, it should be understood that the embodiments described in this specification and the configurations shown in the drawings are merely the most preferred embodiment of the present invention and do not represent the entire technical concept of the present invention, and therefore, various equivalents and modifications that can be substituted therefor may exist at the time of filing this application.

[0042] Terms such as "first" and "second" are used to describe various components, but these terms do not limit the components. These terms are used to distinguish only one component from another, and unless otherwise specified, the first component may be the second component.

[0043] Furthermore, throughout the specification, unless otherwise specified, each element may be singular or plural.

[0044] Hereinafter, when an arbitrary structure is placed "on top (or bottom)" of a component or "above (or below)" a component, it may mean that the arbitrary structure is placed directly on the top (or bottom) surface of the component, but also that another structure may be interposed between the component and the arbitrary structure placed above (or below) the component.

[0045] Furthermore, when a component is described as being "coupled," "coupled," or "connected" to another component, it should be understood that the components may be directly coupled or connected to each other, but that other components may be "intervening" between the components, or that each component may be "coupled," "coupled," or "connected" by other components.

[0046] As used herein, singular expressions include plural expressions unless the context clearly dictates otherwise. In this application, terms such as "comprise" or "include" are not necessarily interpreted as including multiple components or multiple steps described in the specification, and some components or steps may not be included, or additional components or steps may be further included.

[0047] Throughout the specification, unless otherwise specified, "A and / or B" means "A," "B," or "A and B," and "C to D" means at least C and at most D, unless otherwise specified.

[0048] FIG. 2 is a perspective cross-sectional view showing the structure of an electrolyte injection O-ring 60 according to one embodiment of the present invention, and FIG. 3 is a cross-sectional view showing the structure of an electrolyte injection O-ring 60 according to one embodiment of the present invention.

[0049] 2 and 3, an electrolyte injection O-ring 60 according to an embodiment of the present invention may include a main body 61 that is open at its upper and lower ends and defines a cavity 70 along a central axis C, and an expanded diameter portion 62 that extends from the outer circumferential surface of the lower portion of the main body 61 along a centrifugal direction R and the direction of the central axis C. Here, the centrifugal direction R refers to a direction away from the central axis C. The main body 61 may be tubular and surround the central axis C.

[0050] The expanded diameter portion 62 may include an outer peripheral surface 62a that surrounds the central axis C, and a first bottom surface 62b that extends from the lower end of the outer peripheral surface 62a toward the central axis C so as to be substantially perpendicular to the central axis C.

[0051] The expanded diameter portion 62 may include an inclined surface 62c that extends obliquely from the outer circumferential surface of the main body portion 61 along the centrifugal direction R and the direction of the central axis C.

[0052] The expanded diameter portion 62 may include a first upper surface 62d that connects the inclined surface 62c and the outer circumferential surface 62a and is substantially perpendicular to the central axis C.

[0053] The first bottom surface 62b and the first top surface 62d may be annular.

[0054] In a modified example, the inclined surface 62c may extend continuously from the lower end of the outer circumferential surface of the main body portion 61 to the upper end of the outer circumferential surface 62a of the expanded diameter portion 62. In this case, the expanded diameter portion 62 does not need to include the first upper surface 62d.

[0055] The body 61 may have a second upper surface 61a and a second bottom surface 61b at its upper and lower ends, respectively. The second upper surface 61a and the second bottom surface 61b may be substantially parallel to each other and perpendicular to the central axis C. The widths of the second upper surface 61a and the second bottom surface 61b may be the same, or one side may be relatively larger than the other side. The second upper surface 61a and the second bottom surface 61b may be annular.

[0056] The main body 61 may have a groove 61c on its inner circumferential surface facing the cavity 70, the groove 61c being recessed in the centrifugal direction R and extending along the circumferential direction. The groove 61c may surround the central axis C. The cross-sectional shape of the groove 61c may be substantially rectangular. The groove 61c may be used to attach an O-ring for connecting an electrolyte injector (not shown) to the electrolyte injection O-ring 60. If the electrolyte injector is directly connected to the second upper surface 61a, the structure of the groove 61c may be omitted.

[0057] The first bottom surface 62b may be located more outward than the second bottom surface 61b in the centrifugal direction R. The first bottom surface 62b may be located lower than the second bottom surface 61b in the direction of the central axis C.

[0058] The enlarged diameter portion 62 may include a curved surface portion 62e that smoothly connects the first bottom surface 62b and the second bottom surface 61b. The curved surface portion 62e serves to disperse stress, which is generated when the enlarged diameter portion 62 is subjected to pressure from above to below and is elastically deformed in the centrifugal direction R, in the circumferential direction, the centrifugal direction R, and the axial direction C.

[0059] The outer peripheral surface 62a may include a protrusion 62f protruding in the centrifugal direction R. The protrusion 62f may be at least one. When the expanded diameter portion 62 receives pressure from above and moves in the centrifugal direction R, the protrusion 62f may be pressed tightly against the inner peripheral surface between the beading portion 40 of the cylindrical can 10 and the upper end of the cylindrical can 10. The protrusion 62f may be annular and surround the central axis C.

[0060] The electrolyte injection O-ring 60 may be made of a material that does not react with the electrolyte and has insulating and elastic properties. For example, the electrolyte injection O-ring 60 may be made of a rubber material such as silicone.

[0061] The electrolyte injection O-ring 60 may be pressurized downward along the central axis C with the first bottom surface 62b in contact with the horizontal surface of a predetermined structure. In this case, the shape of the expanded diameter portion 62 may be elastically deformed by the pressure, and the diameter of the outer peripheral surface 62a may increase in the centrifugal direction R. This allows the outer peripheral surface 62a to be in close contact with a vertical surface that is substantially perpendicular to the horizontal surface. This completely prevents electrolyte from flowing in through the interface between the outer peripheral surface 62a and the vertical surface and the interface between the first bottom surface 62b and the horizontal surface.

[0062] A method for manufacturing a cylindrical battery using the above-described electrolyte injection O-ring 60 will now be described.

[0063] FIG. 4 is a process diagram illustrating a method for manufacturing a cylindrical battery according to an embodiment of the present invention.

[0064] The method for manufacturing a cylindrical battery according to an embodiment of the present invention includes an electrolyte injection step using an electrolyte injection O-ring 60.

[0065] Referring to FIG. 4, first, a cylindrical can 10 having an open end 10a at one end and a closed end 10b at the other end is prepared.

[0066] Then, a jelly-roll type electrode assembly JR is inserted into the cylindrical can 10. A method for manufacturing the electrode assembly JR will be described later.

[0067] Next, a groove-shaped beading portion 40 recessed toward the central axis C of the cylindrical can 10 is formed at a point spaced a predetermined distance from the open end 10a of the cylindrical can 10. The method for forming the beading portion 40 is well known in the art, and therefore, a detailed description thereof will be omitted.

[0068] The groove shape of the beading portion 40 may include an upper surface 40a and a lower surface 40b facing each other along the direction of the central axis C of the electrode assembly JR. A step A may be formed at a point where the inner peripheral surface 10c of the cylindrical can 10, located between the beading portion 40 and the open end 10a, meets the upper surface 40a of the beading portion 40. Of course, depending on the method for forming the beading portion 40, the step A may not be formed.

[0069] Next, the above-mentioned electrolyte injection O-ring 60 is attached to the open end 10 a of the cylindrical can 10 .

[0070] When installing the electrolyte injection O-ring 60, the first bottom surface 62b of the expanded diameter portion 62 is in contact with the beading portion 40, and the outer peripheral surface 62a of the expanded diameter portion 62 is installed so as to face the inner peripheral surface 10c of the cylindrical can 10 near the open end 10a.

[0071] Next, the electrolyte injector 80 is coupled to the second upper surface 61a of the body 61, and the electrolyte injection O-ring 60 is pressed toward the electrode assembly JR. The pressing direction may be parallel to the central axis C of the cylindrical can 10.

[0072] When the electrolyte injection O-ring 60 is compressed in the direction of the central axis C, the first bottom surface 62b comes into close contact with the upper surface 40a of the beading portion 40. In addition, the shape of the enlarged diameter portion 62 is elastically deformed by pressure, so that the diameter of the outer peripheral surface 62a increases in the centrifugal direction R. As a result, the outer peripheral surface 62a of the enlarged diameter portion 62 comes into close contact with the inner peripheral surface 10c of the cylindrical can 10 located between the beading portion 40 and the open end 10a. For reference, the arrows inside the electrolyte injection O-ring 60 indicate the direction of force transmission when the electrolyte injection O-ring 60 is compressed in the direction of the central axis C.

[0073] If the enlarged diameter portion 62 of the electrolyte injection O-ring 60 has a protrusion 62f, the protrusion 62f can also be compressed and elastically deformed when the electrolyte injection O-ring 60 is pressurized, thereby further improving the adhesion between the outer peripheral surface 62a of the enlarged diameter portion 62 and the inner peripheral surface 10c of the cylindrical can 10.

[0074] Subsequently, the electrolyte E can be injected into the cavity 70 of the main body 61 by the electrolyte injector 80 .

[0075] FIG. 5 is a process diagram showing a method for manufacturing a cylindrical battery according to a preferred embodiment of the present invention.

[0076] Referring to FIG. 5, the method for manufacturing a cylindrical battery according to the present invention may further include the step of interposing a coupling O-ring 90 between the electrolyte injection O-ring 60 and the electrolyte injector 80 .

[0077] The coupling O-ring 90 is a member that assists in tightly coupling the electrolyte injection O-ring 60 and the electrolyte injector 80. The coupling O-ring 90 may include a protrusion 91 that engages with the groove 61c of the main body portion 61. The protrusion 91 may be annular and surround the periphery of the central axis C. The coupling O-ring 90 may include a flange portion 92 that extends in the centrifugal direction R along the second upper surface 61a, and a coupling protrusion 93 that extends upward from the inside of the flange portion 92.

[0078] The electrolyte injector 80 may include a nozzle block 81 that tightly couples to the upper part of the coupling O-ring 90, an electrolyte injection nozzle 83 provided in the nozzle block 81, a guide groove 82 that guides the vertical movement of the electrolyte injection nozzle 83, and a groove that engages with the protrusion 93 of the coupling O-ring 90.

[0079] The electrolyte injection nozzle 83 can be moved up and down by a linear movement mechanism. The outer circumferential surface of the electrolyte injection nozzle 83 has a shape corresponding to the inner circumferential surface of the guide groove 82. The guide groove 82 may have a tapered shape in which the cross-sectional area decreases along the central axis C. After the nozzle block 81 and the coupling O-ring 90 are coupled to each other through protrusion / groove engagement, the electrolyte injection nozzle 83 may move from up to down and come into close contact with the lower part of the guide groove 82. In this state, the electrolyte injection nozzle 83 may spray the electrolyte E onto the upper part of the electrode assembly JR while being in close contact with the guide groove 82.

[0080] The above-described cylindrical battery manufacturing method can be applied to the manufacture of a cylindrical battery having a form factor of 4680 (diameter 46 mm, height 80 mm). Of course, the present invention is not limited by the form factor.

[0081] FIG. 6 is a process diagram illustrating an embodiment of the present invention applied to a cylindrical battery of form factor 4680.

[0082] 6, first, an opening 101 is formed in the closed end 10b of the cylindrical can 10. The opening 101 may be located in the center of the closed end 10b. Then, a rivet terminal 103 is attached between the opening 101 and the closed end 10b with a gasket 102 interposed therebetween.

[0083] The rivet terminal 103 may include a main body portion 103a located within the opening 101, an outer flange portion 103b extending from the lower end of the main body portion 103a along the outer circumferential surface of the closed end 10b in the centrifugal direction R, an inner flange portion 103c bent by firing from the edge of the upper end of the main body portion 103a toward the inner surface of the closed end 10b, and a weld portion 103d provided on the inside of the inner flange portion 103c. An annular recess 103e may be provided between the weld portion 103d and the inner flange portion 103c.

[0084] Next, a positive electrode, a negative electrode, and a separator are prepared to fabricate an electrode assembly JR for a 4680 cylindrical battery. The negative electrode and positive electrode may each be in the form of a sheet having long and short sides. The negative electrode and positive electrode have an uncoated portion at the end of the long side where no active material is present. The uncoated portion may be divided into multiple segments. The segments may be rectangular, trapezoidal, or parallelogram-shaped.

[0085] Next, a stack is formed by interposing a separator between a positive electrode and a negative electrode, each having an uncoated portion at a long edge, and then the stack is wound up along the long edge to fabricate a jelly roll-type electrode assembly JR. The stack may have a structure in which a positive electrode, a separator, a negative electrode, and a separator are stacked in order. Conversely, the stack may have a structure in which a negative electrode, a separator, a positive electrode, and a separator are stacked in order.

[0086] Preferably, when the electrode assembly JR is wound up, the positive electrode and the negative electrode are arranged so that the uncoated portion 105 of the positive electrode and the uncoated portion 106 of the negative electrode face each other along the central axis C. Furthermore, when the electrode assembly JR is wound up, the uncoated portion 105 of the positive electrode and the uncoated portion 106 of the negative electrode are exposed to the outside of the separator by one end and the other end of the electrode assembly JR.

[0087] Next, an end of the positive electrode uncoated portion 105 is bent toward the core 107 of the electrode assembly JR to form a first bent surface region 108. Similarly, an end of the negative electrode uncoated portion 106 is bent toward the core 107 of the electrode assembly JR to form a second bent surface region 109. When the first bent surface region 108 and the second bent surface region 109 are formed, the uncoated portions are stacked in the direction of the central axis C. If the positive electrode uncoated portion 105 and the negative electrode uncoated portion 106 are divided into multiple segments, the flatness of the first bent surface region 108 and the second bent surface region 109 can be improved. In addition, the uncoated portions below the first bent surface region 108 and the second bent surface region 109 can be prevented from being crushed due to excessive bending stress.

[0088] Then, a positive electrode current collector 110 is coupled to the first bent surface region 108, and a negative electrode current collector 111 is coupled to the second bent surface region 109. The structures of the positive electrode current collector 110 and the negative electrode current collector 111 will be described later.

[0089] Next, the electrode assembly JR, in which the positive current collector plate 110 and the negative current collector plate 111 are combined, is inserted into the cylindrical can 10. At this time, the direction of the electrode assembly JR is determined so that the positive current collector plate 110 faces the rivet terminal 103. In addition, an insulator 112 is interposed between the positive current collector plate 110 and the inner surface of the closed end 10b. The insulator 112 provides electrical insulation between the cylindrical can 10 and the positive current collector plate 110. In addition, the structure of the negative current collector 111 can be designed so that the end of the negative current collector 111 contacts the upper surface 40a of the beading portion 40 when the electrode assembly JR is inserted into the cylindrical can 10.

[0090] Next, the positive current collector plate 110 and the rivet terminal 103 are electrically connected. In one example, the positive current collector plate 110 and the weld portion 103d of the rivet terminal 103 are welded to each other through the core 107 of the electrode assembly JR. In addition, the edge portion of the negative current collector plate 111 is electrically connected to the upper surface 40a of the beading portion 40. In one example, at least a portion of the edge portion of the negative current collector plate 111 is welded to the upper surface 40a of the beading portion 40. Laser welding, resistance welding, or ultrasonic welding may be used as the welding method.

[0091] Next, the electrolyte injection O-ring 60 is inserted from the open end 10a of the cylindrical can 10. The outer peripheral surface 62a of the expanded diameter portion 62 of the electrolyte injection O-ring 60 faces the inner peripheral surface 10c of the cylindrical can 10 located between the open end 10a and the beading portion 40, and the first bottom surface 62b contacts the edge of the negative electrode current collector plate 111, which is electrically connected to the upper surface 40a of the beading portion 40.

[0092] Next, in the same manner as injecting the electrolyte solution described above, the electrolyte solution injection O-ring 60 is pressed in the direction of the central axis C, and the electrolyte solution E can be injected into the cylindrical can 10 using the electrolyte solution injector 80. Preferably, a coupling O-ring 90 can be interposed between the electrolyte solution injector 80 and the electrolyte solution injection O-ring 60.

[0093] When the electrolyte injection O-ring 60 is pressurized, the diameter of the outer peripheral surface 62a of the diameter expansion portion 62 increases in the centrifugal direction R due to elastic deformation of the diameter expansion portion 62.

[0094] The first bottom surface 62b of the expanded diameter portion 62 comes into contact with the end of the negative electrode current collector 111 bonded to the upper surface 40a of the beading portion 40 and the upper surface 40a of the beading portion 40 exposed between the end of the circumferentially adjacent negative electrode current collector 111, and presses them in the direction of the central axis C. In addition, the outer peripheral surface 62a of the expanded diameter portion 62 comes into airtight contact with the inner peripheral surface 10c located between the open end 10a of the cylindrical can 10 and the beading portion 40.

[0095] Therefore, it is possible to fundamentally prevent the electrolyte from permeating the upper surface 40a of the beading portion 40 while the electrolyte is being injected into the cylindrical can 10, and remaining on the upper surface 40a of the beading portion 40, particularly on the step A of the upper surface 40a, after the electrolyte is injected.

[0096] FIG. 7 is a plan view showing the structure of a positive current collector plate 110 according to an embodiment of the present invention.

[0097] 6 and 7, a positive current collector plate 110 according to an embodiment of the present invention may include a peripheral portion 110a defining a space S therein, a terminal coupling portion 110b coupled to the welded portion 103d of the rivet terminal 103 inside the peripheral portion 110a, a plurality of non-coated portion coupling portions 110c extending from the inside of the peripheral portion 110a toward the central axis C of the electrode assembly JR and coupled to the first folded surface region 108, and a bridge portion 110d connecting the peripheral portion 110a and the terminal coupling portion 110b.

[0098] The positive electrode current collector plate 110 may optionally further include a tapered portion 110e provided at the boundary region between the peripheral portion 110a and the bridge portion 110d and / or a notched portion 110f in the bridge portion 110d where the cross section is reduced and the resistance is locally increased.

[0099] The tapered portion 110e may be used as a portion for holding the positive current collector plate 110 during a welding process of the positive current collector plate 110 or during a process of transferring the electrode assembly JR to which the positive current collector plate 110 is attached.

[0100] The notch portion 110f locally increases the resistance of the corresponding portion, and therefore can function as a fuse that irreversibly melts the bridge portion 110d when an overcurrent flows through the bridge portion 110d.

[0101] The positive electrode current collector plate 110 has a feature that it has high resistance to externally applied vibrations because the terminal coupling portion 110b and the plurality of non-coated portion coupling portions 110c are separated from each other.

[0102] FIG. 8 is a perspective view showing the structure of a negative electrode current collector plate 111 according to an embodiment of the present invention.

[0103] 6 and 8, the negative electrode current collector plate 111 according to the embodiment of the present invention includes a support portion 111a disposed on the second folded surface region 109 of the electrode assembly JR, a plurality of non-coated portion joining portions 111b extending from one side of the support portion 111a in the centrifugal direction R and joining to the second folded surface region 109, a connecting portion 111c extending obliquely from the other side of the support portion 111a in the axial direction C and the centrifugal direction R, and a beading portion connecting portion 111d extending from an end of the connecting portion 111c in the circumferential direction along the upper surface 40a of the beading portion 40 and electrically connecting to the upper surface 40a of the beading portion 40.

[0104] The connecting portion 111c may be bent at its midpoint. The angle formed by the connecting portion 111c with respect to the support portion 111a may be changed based on the bending point. The angle of the connecting portion 111c located below the bending point may be larger than the angle of the connecting portion 111c located above the bending point. This angle design helps the beading portion connection portion 111d to stably contact the upper surface 40a of the beading portion 40.

[0105] The support portion 111a may have a first hole H1 at its center that communicates with the core 107 of the electrode assembly JR, and the non-coated portion coupling portion 111b may have a second hole H2 at its outer side. The first hole H1 and the second hole H2 are provided to improve impregnation of the electrolyte.

[0106] According to the present invention, when electrolyte injection O-ring 60 is pressed from above in the direction of gravity by electrolyte injector 80, it airtightly contacts upper surface 40a of beading portion 40 and its outer step A, thereby preventing electrolyte from remaining on upper surface 40a of beading portion 40, particularly at step A, even after the electrolyte injection process is completed. As a result, leakage of electrolyte to the outside during the crimping process of the cap assembly or the sizing process of the cylindrical can is prevented, and corrosion of the welded portions of the cylindrical can and bus bar can can be effectively prevented.

[0107] Although the present invention has been described above with reference to limited examples and drawings, the present invention is not limited thereto, and it is of course possible for a person having ordinary skill in the art to which the present invention pertains to make various modifications and variations within the scope of the technical concept of the present invention and the scope of the claims. [Explanation of symbols]

[0108] 10 Cylindrical cans 10a open end 10b closed end 10c Inner surface 40 Beading section 40a top 40b Bottom side 60 Electrolyte injection O-ring 61 Main body 61 61a 2nd top surface 61b 2nd bottom surface 61c Groove 62 Expanded diameter part 62a Outer surface 62b 1st bottom 62c slope 62d 1st top surface 62e Curved section 62f protrusion 70 hollow 80 Electrolyte injector 90 Bonding O-ring 101 Aperture 102 Gasket 103 Rivet terminal 105 Uncoated part of positive electrode 106 Uncoated part of negative electrode 107 cores 108 First Fold Surface Area 109 Second Fold Surface Area 110 Positive current collector plate 111 Negative electrode current collector plate 111a Support part 111b Uncoated part joint 111d Beading joint 112 Insulator

Claims

1. a body portion having open upper and lower ends and defining a cavity along a central axis; an expanded diameter portion extending from a lower portion of the main body portion along the centrifugal direction and the central axis direction, the expanded diameter portion includes an outer circumferential surface surrounding the central axis, An electrolyte injection O-ring, wherein the diameter of the outer circumferential surface increases in the centrifugal direction by elastically deforming the enlarged diameter portion when pressure is applied in the central axial direction.

2. 2. The electrolyte injection O-ring according to claim 1, wherein the expanded diameter portion has a first bottom surface that extends from a lower end of the outer circumferential surface toward the central axis so as to be substantially perpendicular to the central axis.

3. 3. The electrolyte injection O-ring according to claim 1, wherein the expanded diameter portion includes an inclined surface extending obliquely from an outer peripheral surface of the main body portion along the centrifugal direction and the central axis direction.

4. 4. The electrolyte injection O-ring according to claim 3, wherein the enlarged diameter portion includes a first upper surface that connects the inclined surface and the outer circumferential surface of the enlarged diameter portion and is substantially perpendicular to the central axis.

5. The electrolyte injection O-ring of claim 2 , wherein the body portion has a second top surface and a second bottom surface at an upper end and a lower end, respectively.

6. 6. The electrolyte injection O-ring according to claim 5, wherein the main body portion has an inner circumferential surface facing the cavity, the inner circumferential surface being recessed in the centrifugal direction and extending along the circumferential direction.

7. The electrolyte injection O-ring according to claim 5 , wherein the first bottom surface is positioned further outward than the second bottom surface in the centrifugal direction.

8. The electrolyte injection O-ring according to claim 7 , wherein the enlarged diameter portion includes a curved surface portion connecting the first bottom surface and the second bottom surface.

9. 3. The electrolyte injection O-ring according to claim 1, wherein the outer peripheral surface includes a protrusion that protrudes in the centrifugal direction and extends in the circumferential direction.

10. (a) providing a cylindrical can having one open end and the other closed end; (b) inserting a jelly-roll type electrode assembly into the cylindrical can; (c) forming a groove-shaped beading portion at a point spaced a predetermined distance from the open end of the cylindrical can, the beading portion being pressed toward the central axis of the cylindrical can; (d) attaching the electrolyte injection O-ring according to claim 1 or 2 to the inside of the open end of the cylindrical can such that the bottom surface of the enlarged diameter portion of the electrolyte injection O-ring faces the beading portion and the outer circumferential surface of the enlarged diameter portion faces the inner circumferential surface of the cylindrical can near the open end; (e) coupling an electrolyte injector to an upper portion of the body of the electrolyte injection O-ring and pressing the electrolyte injection O-ring toward the electrode assembly; (f) injecting an electrolyte into the cavity of the body with the electrolyte injector.

11. the groove shape of the beading portion includes an upper surface and a lower surface that face each other along the central axis direction, The method for manufacturing a cylindrical battery according to claim 10 , wherein a step is formed in an area where an upper surface of the beading portion contacts an inner peripheral surface of the cylindrical can between the beading portion and the open end.

12. In step (e), The method for manufacturing a cylindrical battery according to claim 10 , wherein the enlarged diameter portion is elastically deformed so that the outer diameter of the outer peripheral surface of the enlarged diameter portion increases in the centrifugal direction.

13. In the step (e), The method for manufacturing a cylindrical battery according to claim 12 , wherein the outer circumferential surface of the expanded diameter portion is in close contact with the inner circumferential surface of the cylindrical can between the beading portion and the open end.

14. In the step (e), The method for manufacturing a cylindrical battery according to claim 13, wherein a protrusion provided on an outer peripheral surface of the enlarged diameter portion is pressed against an inner peripheral surface of the cylindrical can and elastically deformed.

15. forming an opening in the closed end of the cylindrical can and attaching a rivet terminal to the opening with a gasket interposed between the opening and the closed end; forming a laminate having a separator interposed between a positive electrode and a negative electrode, each having an uncoated portion at an end of a long side thereof, and winding the laminate in the long side direction to fabricate a jelly roll type electrode assembly, such that the uncoated portion of the positive electrode and the uncoated portion of the negative electrode are exposed to the outside of the separator at one end and the other end of the electrode assembly, respectively; forming a first folded surface area by folding an uncoated portion of the positive electrode toward a core of the electrode assembly, and bonding a positive electrode current collector to the first folded surface area; bending the uncoated portion of the negative electrode toward the core of the electrode assembly to form a second bent surface area, and bonding a negative electrode current collector to the second bent surface area; inserting the electrode assembly into the cylindrical can such that an insulator is interposed between the positive current collector plate and the closed end and an end of the negative current collector plate is positioned above the beading portion; electrically connecting the positive electrode current collector plate and the rivet terminal; The method of claim 10, further comprising: electrically connecting an end of the negative electrode current collector plate to an upper surface of the beading portion.

16. The negative electrode current collector plate is a support portion disposed around the core; a plurality of uncoated portion coupling portions extending from the support portion and coupling to the second bending surface region; a plurality of beading portion connecting portions extending from the support portion along the centrifugal direction and the winding axis direction toward the beading portion and electrically connecting to an upper portion of the beading portion.

17. The method for manufacturing a cylindrical battery according to claim 16, wherein the bottom surface of the enlarged diameter portion is simultaneously in close contact with the plurality of beading portion connection portions and the upper surface of the beading portion exposed between the circumferentially adjacent beading portion connection portions.

18. (e) before carrying out step The method for manufacturing a cylindrical battery according to claim 16, further comprising interposing a coupling O-ring between the electrolyte injection O-ring and the electrolyte injector.

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