O-ring for electrolyte injection and method for manufacturing cylindrical battery using o-ring

Abstract

The invention provides an O-ring for electrolyte injection and a method for manufacturing a cylindrical battery using the O-ring. According to the present invention, an O-ring for electrolyte injection may comprise: a main body part having an open upper end and an open lower end, and defining a hollow cavity along a central axis thereof; and an expanded diameter portion extending in the centrifugal direction and the central axis direction from the lower outer periphery of the main body portion. The expanded-diameter portion has an outer periphery surrounding a periphery of the central axis, and the expanded-diameter portion may elastically deform when pressure is applied in the axial direction such that a diameter of the outer periphery may increase in the centrifugal direction.

Description

Technical Field

[0001] This application claims priority to Korean Patent Application No. 10-2022-0183770 filed in Korea on December 23, 2022, the disclosure of which is incorporated herein by reference.

[0002] The present invention relates to an electrolyte injection O-ring and a cylindrical battery manufacturing method using the O-ring, and more particularly, to an electrolyte injection O-ring and a cylindrical battery manufacturing method using the O-ring that can prevent electrolyte from remaining in a curling portion. Background Art

[0003] The cylindrical battery includes an electrode assembly wound in a jellyroll shape, a cylindrical can accommodating the electrode assembly and opened at one end; and a cap assembly sealing an upper portion of the cylindrical can.

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

[0005] The edge of the cap assembly is placed on the upper surface of the curling portion. The gasket is inserted between the upper surface of the curling portion and the edge of the cap assembly. The open end of the cylindrical can is clamped along the central axis direction to press the edge of the cap assembly and the gasket together. As a result, the opening of the cylindrical can is tightly sealed by the cap assembly.

[0006] Since the electrolyte is injected before the cap assembly sealing process, the electrode assembly is pre-inserted into the inside of the cylindrical can to be injected with electrolyte. In order to prevent the electrolyte from being discharged to the outside during the electrolyte injection process, an electrolyte injection O-ring is attached to the upper portion of the cylindrical can.

[0007] Figure 1 2 is a cross-sectional view schematically showing a structure in which an electrolyte injection O-ring 20 is coupled to an upper portion of a cylindrical can 10 according to the related art.

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

[0009] Part of the droplets of electrolyte E discharged from electrolyte injector 30 may scatter toward beading portion 40. In addition, if the amount of discharged electrolyte E is relatively greater than the amount of electrolyte E permeated into electrode assembly JR, the liquid level of electrolyte E may rise to the upper portion of beading portion 40.

[0010] A step portion (see 'A') may be formed at a corner where the curling portion 40 and the inner wall of the cylindrical can 10 meet. The step portion A may be formed unintentionally in the process of pressing the top end of the cylindrical can 10 in the direction of gravity so that the upper surface 40a of the curling portion 40 is substantially parallel to the bottom surface of the cylindrical can 10.

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

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

[0013] The scattering of the electrolyte E and the rise in the liquid level of the electrolyte E allow the electrolyte E′ to remain in the step portion A of the bead portion 40 even after the electrolyte is completely injected.

[0014] In a crimping process of mounting the cap assembly together with the gasket on the upper surface 40a of the curled edge portion 40 and then bending and fixing the top end of the cylindrical can 10, or in a sizing process of adjusting the height of the cylindrical can 10 to a designed height by pressing the crimped portion in the gravity direction, the electrolyte E' remaining in the step portion A may leak to the outside of the cylindrical can 10.

[0015] The electrolyte E' leaked to the outside may corrode the outer surface of the cylindrical can 10. In addition, if the electrolyte E' leaked to the outside penetrates into the welding area of ​​the bus bar, the welding area is corroded to increase the resistance of the welding area. In addition, if the corrosion of the welding area is severe, the bus bar may be disconnected. Summary of the invention

[0016] Technical issues

[0017] The present disclosure is intended to solve the problems of the related art, and therefore, the present disclosure is intended to provide an electrolyte injection O-ring having an improved structure to prevent electrolyte from remaining in a step portion of a beaded portion even after an electrolyte injection process is completed.

[0018] The present disclosure also relates to providing a method of manufacturing a cylindrical battery using an electrolyte injection O-ring having an improved structure.

[0019] Technical Solution

[0020] In one aspect of the present disclosure, an electrolyte injection O-ring is provided, comprising: a main body portion having an open top end and an open bottom end 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 a central axis direction.

[0021] The expanded diameter portion may include an outer circumference surrounding the central axis, and the expanded diameter portion may be elastically deformed when pressure is applied in the axial direction such that a diameter of the outer circumference increases in the centrifugal direction.

[0022] The expanded diameter portion may have a first bottom surface extending from a bottom end of the outer circumference toward the central axis so as to be substantially perpendicular to the central axis.

[0023] The expanded diameter portion may include an inclined surface extending obliquely from the outer periphery of the main body portion in the circumferential direction and the central axis direction.

[0024] The expanded diameter portion may include a first upper surface connecting the inclined surface and the outer periphery and being substantially perpendicular to the central axis.

[0025] The body portion may have a second upper surface and a second bottom surface at top and bottom ends thereof, respectively.

[0026] The body portion may have a groove that is recessed in the centrifugal direction and extends in the circumferential direction on an inner circumference facing the cavity.

[0027] The first bottom surface may be positioned more outwardly than the second bottom surface in the centrifugal direction.

[0028] The expanded diameter portion may have a bent portion connecting the first bottom surface and the second bottom surface.

[0029] The outer periphery may include a protrusion that protrudes in the centrifugal direction and extends in the circumferential direction.

[0030] The protrusions may surround a central axis.

[0031] In another aspect of the present disclosure, a method for manufacturing a cylindrical battery is also provided, which includes the following steps: (a) preparing a cylindrical can having an open end at one end and a closed end at the other end; (b) inserting a core-wound electrode assembly into the cylindrical can; (c) forming a curling portion having a groove shape that is press-fitted toward the central axis of the cylindrical can at a point spaced a predetermined distance from the open end of the cylindrical can; (d) installing the above-mentioned electrolyte injection O-ring on the inner side of the open end of the cylindrical can so that the bottom surface of the expanded diameter portion of the electrolyte injection O-ring faces the curling portion, and the outer periphery of the expanded diameter portion faces the inner periphery near the open end; (e) connecting an electrolyte injector to the upper portion of the main body 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 main body through the electrolyte injector.

[0032] The groove shape of the beaded portion may include an upper surface and a lower surface opposite to each other in the central axis direction. The step portion may be formed in a region where the upper surface of the beaded portion meets the inner circumference of the cylindrical can between the beaded portion and the open end.

[0033] In step (e), as the expanded diameter portion is elastically deformed, the outer diameter of the outer periphery of the expanded diameter portion may increase in the centrifugal direction.

[0034] In the step (e), the outer periphery of the expanded diameter portion may be in close contact with the inner periphery of the cylindrical can between the curled edge portion and the open end.

[0035] In the step (e), the protrusion provided on the outer periphery of the expanded diameter portion may be compressed by the inner periphery of the cylindrical can and elastically deformed.

[0036] The cylindrical battery manufacturing method according to the present disclosure may also include the following steps: forming an opening at the closed end of the cylindrical can and installing a riveted terminal by inserting a gasket between the open end and the closed end; manufacturing a jellyroll-type electrode assembly by forming a laminate having a separator interposed between the positive electrode and the negative electrode and winding the laminate in the long side direction, the positive electrode and the negative electrode having an uncoated portion at the end of the long side, so that the uncoated portion of the positive electrode and the uncoated portion of the negative electrode are exposed to the outside of the separator through one end and the other end of the electrode assembly, respectively; and placing the uncoated portion of the positive electrode toward the electrode assembly. The core of the electrode assembly is bent to form a first curved surface area, and the positive current collecting plate is connected to the first curved surface area; the uncoated portion of the negative electrode is bent toward the core of the electrode assembly to form a second curved surface area, and the negative current collecting plate is connected to the second curved surface area; the electrode assembly is inserted into a cylindrical can so that the insulator is interposed between the positive current collecting plate and the closed end, and the edge of the negative current collecting plate is positioned at the upper portion of the curling portion; the positive current collecting plate and the riveted terminal are electrically connected; and the edge of the negative current collecting plate is electrically connected to the upper surface of the curling portion.

[0037] The negative electrode current collector plate may include: a support portion, which is arranged around the core portion; a plurality of uncoated portion connecting portions, which extend from the support portion and are connected to the second curved surface area; and a plurality of curling portion connecting portions, which extend from the support portion toward the curling portion along the centrifugal direction and the winding axis direction and are electrically connected to the upper portion of the curling portion.

[0038] The bottom surface of the expanded diameter portion may be in close contact with the plurality of beaded portion connecting portions at the same time, and the upper surface of the beaded portion is exposed between the beaded portion connecting portions adjacent in the circumferential direction.

[0039] The cylindrical battery manufacturing method according to the present disclosure may further include inserting a coupling O-ring between the electrolyte injection O-ring and the electrolyte injector before performing the (e) step.

[0040] Beneficial Effects

[0041] According to the present disclosure, when the electrolyte injection O-ring is pressed by the electrolyte injector from the top along the gravity direction, the electrolyte injection O-ring is in close contact with the upper surface of the curling portion and the step portion outside it, thereby fundamentally preventing the electrolyte from remaining on the upper surface of the curling portion even after the electrolyte injection process is completed. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] The accompanying drawings illustrate preferred embodiments of the present disclosure and, together with the foregoing disclosure, are used to provide a further understanding of the technical features of the present disclosure, and therefore, the present disclosure is not to be construed as being limited to the accompanying drawings.

[0043] Figure 1 is a cross-sectional view schematically showing a structure in which an electrolyte injection O-ring is coupled to an upper portion of a cylindrical can according to the related art.

[0044] Figure 2 is a perspective cross-sectional view showing the structure of an electrolyte injection O-ring according to an embodiment of the present disclosure.

[0045] Figure 3 is a cross-sectional view showing the structure of an electrolyte injection O-ring according to an embodiment of the present disclosure.

[0046] Figure 4 is a process diagram illustrating a method for manufacturing a cylindrical battery according to an embodiment of the present disclosure.

[0047] Figure 5 is a process diagram showing a method for manufacturing a cylindrical battery according to a preferred embodiment of the present disclosure.

[0048] Figure 6 is a process diagram showing a case in which an embodiment according to the present disclosure is applied to a cylindrical battery having a form factor of 4680.

[0049] Figure 7 is a plan view showing the structure of a positive electrode current collecting plate according to an embodiment of the present disclosure.

[0050] Figure 8 is a perspective view showing the structure of a negative electrode current collecting plate according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0051] Hereinafter, preferred embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. Before the description, it should be understood that the terms used in the specification and the appended claims should not be interpreted as limited to the general and dictionary meanings, but are interpreted on the basis of the meanings and concepts corresponding to the technical aspects of the present disclosure, on the basis of the principle that the inventor is allowed to appropriately define the terms for the best interpretation. Therefore, the descriptions presented herein are only preferred examples for illustrative purposes and are not intended to limit the scope of the present disclosure, and it should be understood that other equivalents and modifications may be made thereto without departing from the scope of the present disclosure.

[0052] Although the terms first, second, etc. are used to describe various elements, these elements are not limited by these terms. These terms are used to distinguish one element from another element, and unless otherwise specified, the first element may be the second element.

[0053] Throughout the specification, unless otherwise specified, each element may be in the singular or in the plural.

[0054] Hereinafter, when an element is “on (or below)” or “over (or under)” another element, the element may be on the upper surface (or lower surface) of the other element, and intermediate elements may exist between the element and the other element on (or under) the element.

[0055] In addition, when an element is referred to as being “connected,” “coupled” or “linked” to another element, the element may be directly connected or coupled to the other element, but it should be understood that there may be intermediate elements between each element, or each element may be “connected,” “coupled” or “linked” to each other through another element.

[0056] Unless the context clearly indicates otherwise, singular expressions used in this specification include plural expressions. In this application, terms such as "include" or "comprise" should not be interpreted as necessarily including all the various components or steps described in the specification, but should be interpreted as some components or some steps may not be included, or may further include additional components or steps.

[0057] In addition, unless the context clearly indicates otherwise, singular expressions used in this specification include plural expressions. In this application, terms such as "include" or "comprise" should not be interpreted as necessarily including all the various components or steps described in the specification, but should be interpreted as some components or some steps may not be included, or may further include additional components or steps.

[0058] Throughout the specification, "A and / or B" refers to A or B or both A and B unless explicitly stated otherwise, and "C to D" refers to above C and below D unless explicitly stated otherwise.

[0059] Figure 2 is a perspective cross-sectional view showing the structure of an electrolyte injection O-ring 60 according to an embodiment of the present disclosure, and Figure 3 is a cross-sectional view showing the structure of the electrolyte injection O-ring 60 according to an embodiment of the present disclosure.

[0060] Reference Figure 2 and Figure 3 The electrolyte injection O-ring 60 according to the embodiment of the present disclosure may include a body portion 61 having an open top end and an open bottom end and defining a cavity 70 along a central axis C, and an expanded diameter portion 62 extending from the lower periphery of the body portion 61 along a centrifugal direction R and a direction of the central axis C. Here, the centrifugal direction R refers to a direction away from the central axis C. The body portion 61 may have a tubular shape around the central axis C.

[0061] The expanded diameter portion 62 may include an outer circumference 62 a surrounding the central axis C and a first bottom surface 62 b extending from a bottom end of the outer circumference 62 a toward the central axis C so as to be substantially perpendicular to the central axis C.

[0062] The expanded diameter portion 62 may include an inclined surface 62 c obliquely extending from the outer periphery of the body portion 61 in the centrifugal direction R and the central axis C direction.

[0063] The expanded diameter portion 62 may include a first upper surface 62 d that connects the inclined surface 62 c and the outer periphery 62 a and is substantially perpendicular to the central axis C.

[0064] The first bottom surface 62b and the first upper surface 62d may have a ring shape.

[0065] In a modification, the inclined surface 62c may extend continuously from the bottom end of the outer periphery of the main body portion 61 to the top end of the outer periphery 62a of the enlarged diameter portion 62. In this case, the enlarged diameter portion 62 may not include the first upper surface 62d.

[0066] The main body 61 may have a second upper surface 61a and a second bottom surface 61b at the top and bottom ends thereof, respectively. The second upper surface 61a and the second bottom surface 61b are substantially parallel and may be 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 have a relatively larger width than the other side. The second upper surface 61a and the second bottom surface 61b may have an annular shape.

[0067] The body portion 61 may have a groove 61c that is recessed in the centrifugal direction R and extends in the circumferential direction on the inner periphery facing the cavity 70. The groove 61c may surround the central axis C. The cross-sectional shape of the groove 61c may be approximately rectangular. The groove 61c may be used to install an O-ring that is used to couple an electrolyte injector (not shown) and the electrolyte injection O-ring 60. If the electrolyte injector is directly coupled to the second upper surface 61a, the structure of the groove 61c may be omitted.

[0068] The first bottom surface 62b may be positioned more outward than the second bottom surface 61b in the centrifugal direction R. The first bottom surface 62b may be located below the second bottom surface 61b in the central axis C direction.

[0069] The enlarged diameter portion 62 may include a curved portion 62e that smoothly connects the first bottom surface 62b and the second bottom surface 61b. The curved portion 62e is used to distribute stress in the circumferential direction, the centrifugal direction R, and the axial direction C, which is generated when the enlarged diameter portion 62 is elastically deformed in the centrifugal direction R by the pressure applied from the top to the bottom.

[0070] The outer periphery 62a may include a protrusion 62f protruding in the centrifugal direction R. At least one protrusion 62f may be provided. When the expanded diameter portion 62 moves in the centrifugal direction R by a pressure applied from the top to the bottom, the protrusion 62f may be compressed to be in close contact with the inner periphery between the curling portion 40 of the cylindrical can 10 and the top end of the cylindrical can 10. The protrusion 62f may have an annular shape around the central axis C.

[0071] 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. In one example, the electrolyte injection O-ring 60 may be made of a rubber material such as silicone.

[0072] The electrolyte injection O-ring 60 can be pressed from top to bottom along the central axis C while the first bottom surface 62b is in contact with the horizontal surface of the predetermined structure. In this case, although the shape of the enlarged diameter portion 62 is elastically deformed due to pressure, the diameter of the periphery 62a can be increased in the centrifugal direction R. Then, the periphery 62a can be brought into close contact with a vertical surface substantially perpendicular to the horizontal plane. Thus, the phenomenon that the electrolyte is introduced through the interface between the periphery 62a and the vertical surface and the interface between the first bottom surface 62b and the horizontal surface can be fundamentally prevented.

[0073] Hereinafter, a method of manufacturing a cylindrical battery using the above-mentioned electrolyte injection O-ring 60 will be described.

[0074] Figure 4 is a process diagram illustrating a method for manufacturing a cylindrical battery according to an embodiment of the present disclosure.

[0075] The cylindrical battery manufacturing method according to an embodiment of the present disclosure includes an electrolyte injection process of injecting the O-ring 60 using an electrolyte.

[0076] Reference Figure 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.

[0077] Next, the jelly jelly type electrode assembly JR is inserted into the cylindrical can 10. A method of manufacturing the electrode assembly JR will be described later.

[0078] Next, a beading portion 40 having a groove shape 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 of forming the beading portion 40 is well known in the art and will therefore not be described in detail here.

[0079] The groove shape of the bead portion 40 may include an upper surface 40a and a lower surface 40a facing each other in the direction of the central axis C of the electrode assembly JR. The step portion A may be provided at a position where the inner periphery 10c of the cylindrical can 10 between the bead portion 40 and the open end 10a meets the upper surface 40a of the bead portion 40. Depending on the method of forming the bead portion 40, the step portion A may not be formed.

[0080] Next, the above-mentioned electrolyte injection O-ring 60 is installed at the open end 10 a of the cylindrical can 10 .

[0081] The electrolyte injection O-ring 60 is installed so that the first bottom surface 62 b of the expanded diameter portion 62 contacts the beaded portion 40 and the outer periphery 62 a of the expanded diameter portion 62 faces the inner periphery 10 c of the cylindrical can 10 near the open end 10 a .

[0082] Next, the electrolyte injector 80 is coupled to the second upper surface 61 a of the body part 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 .

[0083] If the electrolyte injection O-ring 60 is pressed in the direction of the central axis C, the first bottom surface 62b is in close contact with the upper surface 40a of the curling portion 40. In addition, as the shape of the enlarged diameter portion 62 is elastically deformed due to pressure, the diameter of the outer periphery 62a can be increased in the centrifugal direction R. Then, the outer periphery 62a of the enlarged diameter portion 62 can be in close contact with the inner periphery 10c of the cylindrical can 10 located between the curling portion 40 and the open end 10a. For reference, the arrow drawn inside the electrolyte injection O-ring 60 indicates the direction in which the transmission force is when the electrolyte injection O-ring 60 is pressed in the direction of the central axis C.

[0084] 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 pressed. Then, the adhesion between the outer periphery 62a of the enlarged diameter portion 62 and the inner periphery 10c of the cylindrical can 10 can be further improved.

[0085] Subsequently, the electrolyte E may be injected into the cavity 70 of the body part 61 through the electrolyte injector 80 .

[0086] Figure 5 is a process diagram showing a method for manufacturing a cylindrical battery according to a preferred embodiment of the present disclosure.

[0087] Reference Figure 5 The cylindrical battery manufacturing method according to the present disclosure may further include a step of inserting a coupling O-ring 90 between the electrolyte injection O-ring 60 and the electrolyte injector 80 .

[0088] The coupling O-ring 90 is a member that facilitates close coupling of the electrolyte injection O-ring 60 and the electrolyte injector 80. The coupling O-ring 90 may include a protrusion 91 engaged with the groove 61c of the body portion 61. The protrusion 91 may have an annular shape around the central axis C. The coupling O-ring 90 may include a flange portion 92 extending in the centrifugal direction R along the second upper surface 61a and a coupling protrusion 93 extending upward from the inner side of the flange portion 92.

[0089] The electrolyte injector 80 may include: a nozzle block 81 tightly coupled to an upper portion of a coupling O-ring 90, an electrolyte injection nozzle 83 disposed within the nozzle block 81, a guide groove 82 guiding vertical movement of the electrolyte injection nozzle 83, and a groove into which the protrusion 93 of the coupling O-ring 90 is engaged (see "B").

[0090] The electrolyte injection nozzle 83 can be moved up and down by a linear movement mechanism. The outer periphery of the electrolyte injection nozzle 83 has a shape corresponding to the inner periphery of the guide groove 82. The guide groove 82 may have a tapered shape whose 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 by protrusion / groove engagement, the electrolyte injection nozzle 83 may be moved from the top to the bottom and in close contact with the lower portion of the guide groove 82. In this state, the electrolyte injection nozzle 83 may inject the electrolyte E into the upper portion of the electrode assembly JR while in close contact with the guide groove 82.

[0091] The above cylindrical battery manufacturing method can be applied to manufacture a cylindrical battery having a form factor of 4680 (diameter: 46 mm, height: 80 mm). However, the present disclosure is not limited by the form factor.

[0092] Figure 6 is a process diagram showing a case in which an embodiment according to the present disclosure is applied to a cylindrical battery having a form factor of 4680.

[0093] Reference Figure 6 First, an opening 101 is formed at the closed end 10b of the cylindrical can 10. The position of the opening 101 may be the center of the closed end 10b. Then, a rivet terminal 103 is installed while inserting a gasket 102 between the opening 101 and the closed end 10b.

[0094] The riveting terminal 103 may include: a main body 103a located in the opening 101, an outer flange 103b extending from the bottom end of the main body 103a along the outer periphery of the closed end 10b in the centrifugal direction R, and an inner flange 103c bent from the top edge of the main body 103a toward the inner surface of the closed end 10b by plastic working, and a welding portion 103d provided at the inner side of the inner flange 103c. An annular groove 103e may be provided between the welding portion 103d and the inner flange 103c.

[0095] Next, a positive electrode, a negative electrode and a separator are prepared to manufacture an electrode assembly JR included in a 4680 cylindrical battery. The negative electrode and the positive electrode have a sheet shape having a long side and a short side, respectively. The negative electrode and the positive electrode have an uncoated portion without active material at the end of the long side. The uncoated portion can be divided into a plurality of sections. The section can have a shape of a rectangle, a trapezoid, a parallelogram, etc.

[0096] Next, a laminate is constructed in which a separator is interposed between the positive electrode and the negative electrode having an uncoated portion at the end of the long side, and the laminate is wound in the long side direction to manufacture a jellyroll-type electrode assembly JR. The laminate may have a structure in which a positive electrode, a separator, a negative electrode, and a separator are sequentially stacked. Conversely, the laminate may also have a structure in which a negative electrode, a separator, a positive electrode, and a separator are sequentially stacked.

[0097] Preferably, when the electrode assembly JR is wound, 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. In addition, when the electrode assembly JR is wound, 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 through one end and the other end of the electrode assembly JR.

[0098] Next, the end of the positive electrode uncoated portion 105 is bent toward the core 107 of the electrode assembly JR to form a first curved surface area 108. Similarly, the end of the negative electrode uncoated portion 106 is bent toward the core 107 of the electrode assembly JR to form a second curved surface area 109. When the first curved surface area 108 and the second curved surface area 109 are formed, the uncoated portions overlap and stack in the direction of the central axis C. When the positive electrode uncoated portion 105 and the negative electrode uncoated portion 106 are divided into a plurality of sections, the flatness of the first curved surface area 108 and the second curved surface area 109 can be improved. In addition, the uncoated portion can be prevented from being abnormally distorted due to excessive bending stress under the first curved surface area 108 and the second curved surface area 109.

[0099] Subsequently, the positive current collecting plate 110 is coupled to the first curved surface area 108, and the negative current collecting plate 111 is coupled to the second curved surface area 109. The structures of the positive current collecting plate 110 and the negative current collecting plate 111 will be described later.

[0100] Next, the electrode assembly JR to which the positive current collecting plate 110 and the negative current collecting plate 111 are coupled is inserted into the cylindrical can 10. At this time, the direction of the electrode assembly JR is determined so that the positive current collecting plate 110 faces the riveted terminal 103. In addition, the insulator 112 is interposed between the positive current collecting 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 collecting plate 110. In addition, if the electrode assembly JR is inserted into the cylindrical can 10, the structure of the negative current collecting plate 111 can be designed so that the edge of the negative current collecting plate 111 contacts the upper surface 40a of the curling portion 40.

[0101] Next, the positive current collecting plate 110 and the riveted terminal 103 are electrically connected. As an example, the positive current collecting plate 110 and the welding portion 103d of the riveted terminal 103 are welded together through the core 107 of the electrode assembly JR. In addition, the edge of the negative current collecting plate 111 is electrically connected to the upper surface 40a of the curling portion 40. As an example, at least a portion of the edge of the negative current collecting plate 111 is welded to the upper surface 40a of the curling portion 40. Laser welding, resistance welding, or ultrasonic welding may be applied as a welding method.

[0102] Next, the electrolyte injection O-ring 60 is inserted through the open end 10a of the cylindrical can 10. The outer periphery 62a of the enlarged diameter portion 62 of the electrolyte injection O-ring 60 faces the inner periphery 10c of the cylindrical can 10 between the open end 10a and the beaded portion 40, and the first bottom surface 62b contacts the edge of the negative electrode current collecting plate 111 electrically connected to the upper surface 40a of the beaded portion 40.

[0103] Next, as in the above-mentioned electrolyte injection, the electrolyte E may be injected into the cylindrical can 10 using the electrolyte injector 80 in a state where the electrolyte injection O-ring 60 is pressed in the direction of the central axis C. Preferably, the coupling O-ring 90 may be interposed between the electrolyte injector 80 and the electrolyte injection O-ring 60.

[0104] If the electrolyte injection O-ring 60 is pressed, the enlarged diameter portion 62 is elastically deformed, and the diameter of the outer periphery 62 a of the enlarged diameter portion 62 increases in the centrifugal direction R.

[0105] The first bottom surface 62b of the enlarged diameter portion 62 contacts the edge portion of the negative electrode current collecting plate 111 coupled to the upper surface 40a of the beaded portion 40 and the upper surface 40a of the beaded portion 40 exposed between the edge portions of the negative electrode current collecting plate 111 adjacent in the circumferential direction, and presses them in the direction of the central axis C. In addition, the outer periphery 62a of the enlarged diameter portion 62 is in close contact with the inner periphery 10c located between the open end 10a of the cylindrical can 10 and the beaded portion 40.

[0106] Therefore, when the electrolyte is injected into the cylindrical can 10, the electrolyte can be fundamentally prevented from penetrating into the upper surface 40a of the beaded portion 40 and remaining on the upper surface 40a of the beaded portion 40 after the electrolyte is injected, especially the step portion A of the upper surface 40a.

[0107] Figure 7 is a plan view showing the structure of a positive electrode current collecting plate 110 according to an embodiment of the present disclosure.

[0108] Reference Figure 6 and Figure 7According to an embodiment of the present disclosure, the positive current collecting plate 110 includes: an edge portion 110a, which defines an empty space S inside; and a terminal connecting portion 110b, which is connected to the welding portion 103d of the riveted terminal 103 on the inner side of the edge portion 110a; a plurality of uncoated portion connecting portions 110c, which extend from the inner side of the edge portion 110a toward the central axis C of the electrode assembly JR and are connected to the first curved surface area 108; and a bridging portion 110d, which connects the edge portion 110a and the terminal connecting portion 110b.

[0109] Alternatively, the positive current collecting plate 110 may further include a tapered portion 110e disposed at a boundary region between the edge portion 110a and the bridge portion 110d and / or a groove portion 110f in which a cross section of the bridge portion 110d is reduced to partially increase resistance.

[0110] The tapered portion 110 e may be used as a member for clamping the positive current collecting plate 110 in a process of welding the positive current collecting plate 110 or during a process of transporting the electrode assembly JR to which the positive current collecting plate 110 is coupled.

[0111] The slotted portion 110f locally increases the resistance of the corresponding region. Therefore, the slotted portion 110f may function as a fuse that irreversibly melts and cuts the bridge portion 110d when an overcurrent flows through the bridge portion 110d.

[0112] Since the terminal coupling portion 110 b and the plurality of non-coating portion coupling portions 110 c are separated from each other, the positive electrode current collecting plate 110 has strong resistance to vibration applied from the outside.

[0113] Figure 8 is a perspective view showing the structure of a negative electrode current collecting plate 111 according to an embodiment of the present disclosure.

[0114] Reference Figure 6 and Figure 8 According to an embodiment of the present disclosure, the negative electrode current collecting plate 111 includes: a support portion 111a, which is arranged on the second curved surface area 109 of the electrode assembly JR; a plurality of uncoated portion connecting portions 111b, which extend from one side of the support portion 111a in the centrifugal direction R and are connected to the second curved surface area 109; a connecting portion 111c, which extends obliquely from the other side of the support portion 111a in the axial direction C and the centrifugal direction R; and a curling portion connecting portion 111d, which extends from an end of the connecting portion 111c along the upper surface 40a of the curling portion 40 in the circumferential direction and is electrically connected to the upper surface 40a of the curling portion 40.

[0115] The connecting portion 111c may be bent at an intermediate bending point. The angle formed by the connecting portion 111c relative to the supporting portion 111a may change based on the bending point. The angle of the connecting portion 111c located below the bending point may be greater than the angle of the connecting portion 111c located above the bending point. This angle design helps the hemming connecting portion 111d to stably contact the upper surface 40a of the hemming portion 40.

[0116] The support portion 111a may have a first hole H1 formed in a central portion to communicate with the core portion 107 of the electrode assembly JR, and the non-coating portion coupling portion 111b may have a second hole H2 at the outer side. The first hole H1 and the second hole H2 are provided to improve impregnation of the electrolyte.

[0117] According to the present disclosure, when the electrolyte injection O-ring 60 is pressed by the electrolyte injector 80 from the top in the gravity direction, the electrolyte injection O-ring 60 is closely adhered to the upper surface 40a of the bead portion 40 and the step portion A at the outside thereof, so that even after the electrolyte injection process is completed, the electrolyte can be prevented from remaining on the upper surface 40a of the bead portion 40 (especially on the step portion A). As a result, during the process of crimping the cap assembly or the process of shaping the cylindrical can, external leakage of the electrolyte can be prevented, thereby effectively preventing the cylindrical can or the bus bar welding portion from being corroded.

[0118] The present disclosure has been described in detail. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the present disclosure, are given by way of illustration only, as various changes and modifications within the scope of the present disclosure will become apparent to those skilled in the art from the detailed description.

Claims

1. An electrolyte injection O-ring, the electrolyte injection O-ring comprising: a main body portion having an open top end and an open bottom end and defining a cavity along a central axis; as well as an expanded diameter portion, the expanded diameter portion extending from the lower portion of the main body portion in a centrifugal direction and a central axis direction, wherein the expanded diameter portion includes an outer circumference surrounding the central axis, and When pressure is applied in the axial direction, the diameter-enlarging portion is elastically deformed so that the diameter of the outer circumference increases in the centrifugal direction.

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

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

4. The electrolyte injection O-ring according to claim 3, in, The expanded diameter portion includes a first upper surface connecting the inclined surface and the outer periphery and being substantially perpendicular to the central axis.

5. The electrolyte injection O-ring according to claim 1, in, The body portion has a second upper surface and a second bottom surface at the top end and the bottom end, respectively.

6. The electrolyte injection O-ring according to claim 5, in, The main body portion has a groove which is recessed in the centrifugal direction on an inner periphery facing the cavity and extends in a circumferential direction.

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

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

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

10. A method for manufacturing a cylindrical battery, comprising the following steps: (a) preparing a cylindrical can having an open end at one end and a closed end at the other end; (b) inserting a jelly jelly-type electrode assembly into the cylindrical can; (c) forming a bead portion having a groove shape press-fitted toward a central axis of the cylindrical can at a point spaced a predetermined distance from the open end of the cylindrical can; (d) installing the electrolyte injection O-ring according to any one of claims 1 to 9 inside the open end of the cylindrical can so that the bottom surface of the expanded diameter portion of the electrolyte injection O-ring faces the curled edge portion and the outer periphery of the expanded diameter portion faces the inner periphery near the open end; (e) coupling an electrolyte injector to an upper portion of the 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 main body portion through the electrolyte injector.

11. The method for manufacturing a cylindrical battery according to claim 10, in, The groove shape of the curling portion includes an upper surface and a lower surface that are opposite to each other along the central axis direction, and wherein a step portion is formed in a region where an upper surface of the beaded portion meets the inner circumference of the cylindrical can between the beaded portion and the open end.

12. The method for manufacturing a cylindrical battery according to claim 10, in, In step (e), as the expanded diameter portion is elastically deformed, the outer diameter of the outer circumference of the expanded diameter portion increases in the centrifugal direction.

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

14. The method for manufacturing a cylindrical battery according to claim 13, in, In the step (e), the protrusion provided on the outer periphery of the expanded diameter portion is compressed by the inner periphery of the cylindrical can and elastically deformed.

15. The method for manufacturing a cylindrical battery according to claim 10, further comprising the following steps: forming an opening at the closed end of the cylindrical can and installing a riveted terminal by inserting a gasket between the open end and the closed end; manufacturing a jelly-roll type electrode assembly by forming a laminate having a separator interposed between a positive electrode and a negative electrode, the positive electrode and the negative electrode having uncoated portions at ends of the long sides, and winding the laminate in a long-side direction so that the uncoated portion of the positive electrode and the uncoated portion of the negative electrode are exposed to the outside of the separator through one end and the other end of the electrode assembly, respectively; bending the non-coated portion of the positive electrode toward a core portion of the electrode assembly to form a first curved surface region, and coupling a positive electrode current collecting plate to the first curved surface region; bending the non-coating portion of the negative electrode toward the core portion of the electrode assembly to form a second curved surface region, and coupling a negative electrode current collecting plate to the second curved surface region; inserting the electrode assembly into the cylindrical can so that an insulator is interposed between the positive current collecting plate and the closed end and an edge of the negative current collecting plate is positioned at an upper portion of the curled portion; electrically connecting the positive electrode current collecting plate and the riveted terminal; and An edge of the negative electrode current collecting plate is electrically connected to an upper surface of the curling portion.

16. The method for manufacturing a cylindrical battery according to claim 15, in, The negative electrode current collecting plate comprises: a support portion, the support portion being disposed around the core portion; a plurality of uncoated portion coupling portions extending from the support portion and coupled to the second curved surface area; and A plurality of curling portion connecting portions extend from the support portion toward the curling portion in the centrifugal direction and the winding axis direction and are electrically connected to the upper portion of the curling portion.

17. The method for manufacturing a cylindrical battery according to claim 16, in, The bottom surface of the expanded diameter portion is in close contact with both the plurality of beaded portion connecting portions and the upper surface of the beaded portion exposed between the beaded portion connecting portions adjacent in the circumferential direction.

18. The method for manufacturing a cylindrical battery according to claim 16, before performing the step (e), the method for manufacturing a cylindrical battery further comprises the following steps: A coupling O-ring is interposed between the electrolyte injection O-ring and the electrolyte injector.

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