Secondary battery

Abstract

According to one aspect of the present disclosure, there may be provided a secondary battery including: an electrode assembly including a positive electrode, a negative electrode, and a separator; a can accommodating the electrode assembly; the first current collector is electrically connected with the electrode assembly and comprises a current collecting column protruding upwards and a liquid injection port penetrating through the current collecting column up and down; a first electrode terminal electrically connected to the first current collector and coupled to the tank; and a cover part configured to seal the liquid injection port. According to the secondary battery disclosed by the invention, the energy density can be improved, a hole at the bottom of the secondary battery is not formed, and the internal resistance of the positive current collector and the positive terminal part of the secondary battery is reduced.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to a secondary battery and a method of manufacturing a secondary battery. BACKGROUND

[0002] A secondary battery is one of energy storage devices that can be charged and discharged. The secondary battery is widely used in various devices that use electricity as a power source. As an example, the secondary battery is used as an energy storage device in various devices from small devices such as a mobile phone, a notebook computer, a tablet computer, etc. to large devices such as a vehicle, an aircraft, etc. In particular, recently, the application of the secondary battery as a power source for a vehicle is actively being explored.

[0003] Depending on the electrode material, the secondary battery can be classified into a lead-acid battery, a nickel-cadmium battery, a nickel-hydrogen battery, a lithium-ion battery, etc. Each type of secondary battery can be appropriately selected depending on the design capacity, the use environment, etc. Alternatively, the secondary battery can be an all-solid-state battery that uses a solid electrolyte instead of a liquid electrolyte. Compared to other types of secondary batteries, the lithium-ion battery can achieve a relatively high voltage and capacity. Therefore, the lithium-ion battery is widely used in fields requiring a high-density energy storage device such as a battery pack for a vehicle.

[0004] The secondary battery such as a lithium secondary battery can include a positive electrode plate, a negative electrode plate, a separator, an electrolyte, etc. The positive electrode plate and the negative electrode plate are disposed apart by the separator of an insulating material, and charging or discharging can be achieved by the movement of ions based on the electrolyte.

[0005] The secondary battery is manufactured by a pouch-type battery cell having flexibility or a square or cylindrical can-type battery cell having rigidity. SUMMARY

[0006] TECHNICAL PROBLEM

[0007] According to one aspect of the present disclosure, a process for a secondary battery can be improved.

[0008] According to one aspect of the present disclosure, the energy density of a secondary battery can be improved.

[0009] According to one aspect of the present disclosure, a hole of a bottom of a secondary battery can not be formed.

[0010] According to one aspect of the present disclosure, the internal resistance of a positive electrode current collector and a positive electrode terminal portion of a secondary battery can be reduced.

[0011] The secondary battery and the secondary battery manufacturing method of the present disclosure can be widely applied to the eco-friendly technical field of electric vehicles, battery charging stations, and the like. Also, the secondary battery and the secondary battery manufacturing method of the present disclosure can be used for eco-friendly electric vehicles, hybrid vehicles, and the like that prevent climate change by suppressing the emission of atmospheric pollution and greenhouse gases.

[0012] Technical solutions

[0013] The secondary battery according to the present disclosure can include an electrode assembly including a cathode, an anode, and a separator; a can accommodating the electrode assembly; a first current collector electrically connected with the electrode assembly, including a current collecting post protruding upward, and a liquid injection port penetrating the current collecting post upward and downward; a first electrode terminal electrically connected with the first current collector, combined with the can; and a cap portion configured to seal the liquid injection port.

[0014] According to one embodiment, the first current collector can include a current collecting plate configured in an upper portion of the electrode assembly and having a disc shape to provide the current collecting post.

[0015] According to one embodiment, the current collecting plate can be electrically connected with a first electrode foil of the electrode assembly.

[0016] According to one embodiment, the first electrode terminal can include a terminal post in contact with the current collecting post to be electrically connected.

[0017] According to one embodiment, the first electrode terminal can further include an outer terminal located in an upper portion of the terminal post and extending in a horizontal direction, and an inner terminal located in a lower portion of the terminal post and extending in the horizontal direction.

[0018] According to one embodiment, the current collecting post can be in contact with an inner side of the terminal post to be electrically connected.

[0019] According to one embodiment, the can includes a main body portion of which at least one of an upper portion and a lower portion is open, and can include a first sealing portion sealing the upper portion of the main body portion, and a second sealing portion sealing the lower portion of the main body portion.

[0020] According to one embodiment, at least one of the first sealing portion and the second sealing portion can be integrated with the main body portion.

[0021] According to one embodiment, the first electrode terminal can be combined with the can through the first sealing portion.

[0022] According to one embodiment, the second sealing portion can be electrically connected with a second electrode foil of the electrode assembly.

[0023] According to one embodiment, the first sealing part can include a second coupling hole into which the current collector post and the first electrode terminal are inserted.

[0024] According to one embodiment, a gasket sealing between the first electrode terminal and the first sealing part can be further included.

[0025] According to one embodiment, the cap part can include a shape of a rivet inserted into the liquid injection hole to be coupled.

[0026] According to one embodiment, the cap part can include a rivet post inserted into the liquid injection hole and a rivet head located at an upper portion of the rivet post and extending in a horizontal direction.

[0027] According to one embodiment, an upper portion of the first electrode terminal can include a shape corresponding to the rivet head to be coupled with the rivet head.

[0028] According to another embodiment, the cap part can include a disc shape covering an upper portion of the liquid injection hole.

[0029] According to another embodiment, the current collector post includes a protruding head extending in a horizontal direction at one end of an upper portion, and the cap part can be in contact with the protruding head.

[0030] In addition, a secondary battery manufacturing method according to the disclosure can include a second electrode welding step of electrically connecting a second electrode foil of an electrode assembly including a positive electrode, a negative electrode, and a separator to a second sealing part, an electrode assembly insertion step of inserting the electrode assembly into a main body part of a can, a first electrode welding step of electrically connecting a first electrode foil of the electrode assembly to a first current collector, a current collector post insertion step of inserting a current collector post of the first current collector into a first electrode terminal to be electrically connected, a liquid injection step of injecting an electrolyte into a liquid injection hole penetrating through the current collector post in an upward and downward direction, and a sealing step of sealing the liquid injection hole with a cap part.

[0031] According to one embodiment, a lower welding step of welding the second sealing part to the main body part can be included.

[0032] According to one embodiment, an upper welding step of welding a first sealing part into which the first electrode terminal is inserted to the main body part can be included.

[0033] Technical Effects

[0034] According to one embodiment of the disclosure, a process of a secondary battery can be improved.

[0035] According to one embodiment of the disclosure, an energy density of a secondary battery can be improved.

[0036] According to one embodiment of the disclosure, a hole of a bottom of a secondary battery can not be formed.

[0037] According to one embodiment of the present disclosure, internal resistance of a positive electrode current collector and a positive terminal portion of a secondary battery can be reduced. BRIEF DESCRIPTION OF DRAWINGS

[0038] Figure 1 FIG. 1 is an exploded perspective view of a secondary battery according to the present disclosure;

[0039] Figure 2 FIG. 2 is a cross-sectional view of the secondary battery of FIG. 1;

[0040] Figure 3 FIG. 3 is a cross-sectional view of the secondary battery of FIG. 1;

[0041] Figure 4 FIG. 4 is a cross-sectional view of the secondary battery of FIG. 1;

[0042] Figure 5 FIG. 5 is an exploded cross-sectional view of the secondary battery of FIG. 1;

[0043] Figure 6 FIG. 6 is a cross-sectional view of a secondary battery according to another embodiment of the present disclosure;

[0044] Figure 7 FIG. 7 is a flowchart of a method of manufacturing a secondary battery according to the present disclosure;

[0045] Figure 8 FIG. 8 is a flowchart of a method of manufacturing a secondary battery according to the present disclosure;

[0046] Figure 9 FIG. 9 is a flowchart of a method of manufacturing a secondary battery according to the present disclosure;

[0047] Figure 10 FIG. 10 is a flowchart of a method of manufacturing a secondary battery according to the present disclosure;

[0048] Figure 11 FIG. 11 is a flowchart of a method of manufacturing a secondary battery according to the present disclosure.

[0049] BRIEF DESCRIPTION OF DRAWINGS

[0050] 10: secondary battery 100: electrode assembly

[0051] 110: first electrode foil 120: second electrode foil

[0052] 200: can 210: first sealing portion

[0053] 211: second coupling hole 220: second sealing portion

[0054] 230: main body portion 300: first current collector

[0055] 310: current collecting post 311: liquid injection port

[0056] 312: protruding head 320: current collecting plate

[0057] 400: first electrode terminal 410: terminal post

[0058] 411: first coupling hole 420: external terminal

[0059] 430: internal terminal 500: cover portion

[0060] 500a: rivet-shaped cover portion 510a: rivet post

[0061] 520a: rivet head 500b: disc-shaped cover portion

[0062] 600: gasket DETAILED DESCRIPTION

[0063] Embodiments of the present disclosure will be described below with reference to the accompanying drawings. In the following description, detailed description of configurations or well-known configurations that make the technical gist of the present disclosure unclear will be omitted for convenience.

[0064] The following embodiments are provided in order to more completely describe the present application to those having ordinary skill in the art to which the present application pertains. The following embodiments are provided in order to help understanding of the present application, and the technical idea of the present application is not necessarily limited to the specific embodiments described below. It should be understood that the present disclosure broadly includes various equivalents, alternatives, modifications, and the like of the technical idea described in the following embodiments.

[0065] From the above viewpoint, the terms used in the following embodiments are provided in order to more completely describe the specific embodiments. Therefore, the terms used in the following embodiments should not be interpreted for the purpose of narrowing, limiting, or restricting the technical idea of the present disclosure, and the like.

[0066] In the following description, singular expressions can be interpreted to include plural meanings unless clearly excluded from the context. In addition, in the following description, "comprise" means that the configurations, parts, operations, features, steps, numbers, and the like described in the description are present, and does not mean that additional one or more other configurations, parts, operations, features, steps, numbers, and the like are excluded.

[0067] The secondary battery or battery cell described in the present specification can include a battery that can be charged and discharged, and as an example, the secondary battery can include a lead-acid battery, a nickel-cadmium battery, a nickel-hydrogen battery, a lithium-ion battery, or the like. In the present specification, a case in which the secondary battery is a lithium secondary battery is mainly described. However, it should be understood that the technical concept described in the present specification can also be applied to other suitable types of batteries other than the lithium secondary battery.

[0068] Before the present disclosure is disclosed in detail, the terms or words used in the specification and the technical solutions described below in the specification should not be interpreted as being explained in the meaning in the conventional or dictionary, but should be based on the principle that the inventor can appropriately define the concept of the terms in order to explain his own utility model in the best method, and be interpreted as the meaning and concept consistent with the technical idea of the present disclosure. Therefore, the embodiments described in the present specification and the configurations shown in the drawings are only the most preferred embodiments of the present disclosure, and do not represent the entire technical idea of the present disclosure, and it should be understood that there can be a variety of equivalents and modifications that can replace them at the time of filing the present application.

[0069] Hereinafter, preferred embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. At this time, it should be noted that in the drawings, the same constituent elements are denoted by the same reference numerals as far as possible. Also, detailed description about well-known functions and configurations that can obscure the gist of the present disclosure will be omitted. For the same reason, some of the constituent elements in the drawings are exaggeratedly illustrated or omitted or simply illustrated, and the size of each constituent element does not completely reflect the actual size. For example, in the present specification, the expressions of upper side, upper portion, upper, lower side, lower portion, lower, side, etc. are explained based on the illustration, and if the direction of the relevant object is changed, it can be described in other ways.

[0070] Hereinafter, a secondary battery and a secondary battery manufacturing method according to the present disclosure will be described in detail with reference to the accompanying drawings.

[0071] Figure 1 To show an exploded perspective view of the secondary battery 10 according to the present disclosure, Figure 2 To show a cross-sectional view of the secondary battery 10 of one embodiment, Figure 3 To show a cross-sectional view of the secondary battery 10 of one embodiment, Figure 4 To show a cross-sectional view of the secondary battery 10 of one embodiment, Figure 5 To show an exploded cross-sectional view of the secondary battery 10 of one embodiment.

[0072] Figures 1 to 2 To show a case in which the upper and lower portions of the main body portion 230 are entirely open, Figure 3 To show a case in which the lower portion of the main body portion 230 is open, Figure 4 To show a case in which the upper portion of the main body portion 230 is open.

[0073] Referring to Figures 1 to 5 The secondary battery 10 according to the present disclosure can include an electrode assembly 100, a can 200, a first current collector 300, a first electrode terminal 400, and a cap portion 500.

[0074] The electrode assembly 100 can include a positive electrode, a negative electrode, and a separator. The separator can be configured of an insulator located between the negative electrode and the positive electrode. The electrode assembly 100 can be configured in a stack type in which the positive electrode, the negative electrode, and the separator are alternately stacked. Alternatively, the electrode assembly 100 can be configured in a jelly roll type in which the positive electrode, the negative electrode, and the separator located between the positive electrode and the negative electrode are alternately stacked and wound in a roll shape. Although the electrode assembly 100 is illustrated in the jelly roll type in the present disclosure, it is not necessarily limited thereto.

[0075] The positive electrode and the negative electrode can each have a structure in which a positive active material or a negative active material is coated on a foil. For example, the negative electrode can be formed by coating graphite or the like on a foil of copper or nickel, and the positive electrode can be formed by coating a transition metal oxide active material on a foil of aluminum.

[0076] The first electrode can be a positive electrode, and the second electrode can be a negative electrode. Alternatively, according to circumstances, the first electrode can be a negative electrode, and the second electrode can be a positive electrode. However, in the present disclosure, the first electrode is described as a positive electrode, and the second electrode is described as a negative electrode.

[0077] The electrode assembly 100 can include a first electrode foil 110 and a second electrode foil 120. At least a portion of the positive electrode and the negative electrode can not be coated with the active material. Portions of the positive electrode and the negative electrode, in which the active material is not coated, can be referred to as uncoated portions, respectively. At least a portion of the uncoated portions can be referred to as the first electrode foil 110 and the second electrode foil 120. Here, the first electrode foil 110 and the second electrode foil 120 can each protrude upward and downward. Referring to Figure 2 The first electrode foil 110 can protrude upward from the electrode assembly 100, and the second electrode foil 120 can protrude downward from the electrode assembly 100.

[0078] The can 200 can accommodate the electrode assembly 100. In other words, the can 200 can be referred to as a case. The can 200 can be formed to include an empty space for accommodating the electrode assembly 100 in the inside. The can 200 can include a cylindrical or columnar shape. Accordingly, the cylindrical or columnar can 200 can include an empty space of a cylindrical or columnar shape in the inside, and the electrode assembly 100 can be accommodated in the empty space.

[0079] The can 200 can include a main body portion 230, a first sealing portion 210, and a second sealing portion 220. The can 200 can include a material having electrical conductivity. For example, it can be nickel-plated steel, stainless steel, aluminum, or the like.

[0080] The body part 230 can be a member open at least one of the upper and lower portions. That is, the body part 230 can be open at least one of the upper and lower faces. As shown, the body part 230 can be open at both the upper and lower portions, or as shown, the body part 230 can be open at the lower portion, or as shown, the body part 230 can be open at the upper portion. Figure 2 Figure 3 Figure 4 The electrode assembly 100 can be inserted into the inside of the can 200 through the open upper or lower face. As to whether the electrode assembly 100 is inserted through the upper face or the lower face of the body part 230, it can vary according to the order of the manufacturing method. The body part 230 can have various shapes, for example, the body part 230 can include a cylindrical shape or a circular cylindrical shape.

[0081] The first sealing part 210 can seal the upper portion of the body part 230. For example, in the case where the upper portion of the body part 230 is open, the first sealing part 210 can be combined with the body part 230 at the upper portion of the body part 230 to seal the open upper portion of the body part 230. The manner of sealing the upper portion of the body part 230 can employ various manners, but in the present disclosure, welding is exemplified. The welding can employ various welding manners. For example, laser welding can be employed. The first sealing part 210 and the body part 230 can have shapes corresponding to each other on the facing faces so as to be combined with each other. The edge of the first sealing part 210 can be welded in the state where the first sealing part 210 is combined with the body part 230.

[0082] Alternatively, in the case where the lower portion of the body part 230 is open and the upper portion is sealed, the first sealing part 210 can be the sealed upper portion of the body part 230. Accordingly, the first sealing part 210 can be combined in the state of being separated from the body part 230, or can be integrated with the body part 230.

[0083] The first sealing part 210 can include a second combining hole 211. The second combining hole 211 can be a hole into which the current collecting post 310 and the first electrode terminal 400, which will be described later, are inserted. For example, the first sealing part 210 can include a disc shape, and a hole passing through the upper and lower portions can be formed in the middle, which can be the second combining hole 211.

[0084] The second sealing part 220 can seal the lower portion of the body part 230. For example, in the case where the lower portion of the body part 230 is open, the second sealing part 220 can be combined with the body part 230 at the lower portion of the body part 230 to seal the open lower portion of the body part 230. The lower portion of the body part 230 can be sealed in various manners like the upper portion, but can be sealed by the welding manner. The edge of the second sealing part 220 can be welded in the state where the second sealing part 220 is combined with the lower portion of the body part 230. ​​

[0085] Alternatively, in a case where the upper portion of the body portion 230 is open and the lower portion is sealed, the second sealing portion 220 can be the sealed lower portion of the body portion 230. Accordingly, the second sealing portion 220 can be coupled in a state of being separated from the body portion 230, or can be integrated with the body portion 230.

[0086] That is, referring to Figure 2 In a case where the upper portion and the lower portion of the body portion 230 are open, the first sealing portion 210 and the second sealing portion 220 can be coupled in a state of being separated from the body portion 230. Alternatively, referring to Figures 3 to 4 In a case where any one of the upper portion and the lower portion of the body portion 230 is open, at least one of the first sealing portion 210 and the second sealing portion 220 can be integrated with the body portion 230, and the other can be coupled in a state of being separated from the body portion 230.

[0087] The second sealing portion 220 can include a disc shape. In this case, the second sealing portion 220 can not be formed with a hole. In other words, the second sealing portion 220 can be a bottom portion of the secondary battery 10. In a process of manufacturing the existing secondary battery 10, a process of forming a hole in the bottom portion of the secondary battery 10, inserting a welding rod or injecting an electrolyte solution into the hole, and then sealing the hole is performed. However, the second sealing portion 220 of the secondary battery 10 structure according to the disclosure has a structure in which the hole does not need to be formed.

[0088] The second sealing portion 220 can be electrically connected with the second electrode foil 120 of the electrode assembly 100. For example, the second sealing portion 220 can be welded with the second electrode foil 120. The second sealing portion 220 has electrical conductivity, and thus can be electrically connected with each other by being welded with the second electrode foil 120.

[0089] On the contrary, the first sealing portion 210 can not be electrically connected with the first electrode foil 110. For example, the secondary battery 10 can further include a gasket 600. The gasket 600 can seal between the first electrode terminal 400 and the first sealing portion 210, and can include an insulator. The first electrode terminal 400 can be in a state of being electrically connected with the first electrode foil 110. Accordingly, the gasket 600 can prevent the first sealing portion 210 from being electrically connected with the first electrode foil 110.

[0090] The first current collector 300 can be electrically connected with the electrode assembly 100. For example, the first current collector 300 can be electrically connected with the first electrode foil 110 of the electrode assembly 100. Here, the first current collector 300 and the first electrode foil 110 can be electrically connected by welding or the like.

[0091] The first current collector 300 can include a current collecting plate 320, a current collecting pillar 310, and a liquid injection port 311.

[0092] The current collecting plate 320 can be a plate having a disc shape configured at an upper portion of the electrode assembly 100 and providing the current collecting post 310. For example, the current collecting plate 320 can include a disc shape having a hole formed in the middle thereof. One surface of a flat lower portion of the current collecting plate 320 can be in contact with an upper portion of the electrode assembly 100. In particular, one surface of the lower portion of the current collecting plate 320 can be in contact with the first electrode foil 110 of the electrode assembly 100. The current collecting plate 320 can be electrically connected with the first electrode foil 110. Here, the current collecting plate 320 and the first electrode foil 110 can be electrically connected by welding or the like.

[0093] The current collecting post 310 can protrude upward. For example, the current collecting post 310 can have a shape protruding upward from the periphery of the hole formed in the middle of the current collecting plate 320. The current collecting post 310 can be formed in various shapes. For example, the current collecting post 310 can include a cylindrical or columnar shape. However, this is merely an example and is not necessarily limited thereto, and can also be a quadrangular column or triangular column shape.

[0094] Here, the hole passing through the current collecting post 310 upward and downward can be the injection port 311. That is, the inside of the current collecting post 310 is formed with a hole, which can be the injection port 311. The injection port 311 can be a hole for injecting an electrolyte solution.

[0095] The first electrode terminal 400 can be electrically connected with the first current collector 300. The first electrode terminal 400 can be formed of a material having electrical conductivity. For example, the first electrode terminal 400 and the first current collector 300 can be electrically connected by contacting each other by at least a portion thereof.

[0096] In particular, the first electrode terminal 400 can include a first coupling hole 411 into which the current collecting post 310 is inserted. The first electrode terminal 400 can include a terminal post 410 in which the first coupling hole 411 is formed in the inside. The terminal post 410 can have various shapes. For example, the terminal post 410 can include a cylindrical or columnar shape. The inside of the terminal post 410 has an empty space, which can be the first coupling hole 411. In this case, the current collecting post 310 can be electrically connected by contacting the inside of the terminal post 410. The inside of the terminal post 410 can include a shape corresponding to the outside of the current collecting post 310 so as to be in close contact with the current collecting post 310.

[0097] The terminal post 410 and the current collecting post 310 can be electrically connected by contacting each other by a surface and a surface. Accordingly, the greater the contact area, the smaller the electrical resistance can be. In other words, the internal resistance of the positive current collector and the positive terminal portion can be reduced. The contact area is adjustable. For example, the contact area can be expanded by increasing the length of the terminal post 410 and the current collecting post 310 from each other, or by increasing the diameter of each.

[0098] The first electrode terminal 400 can be combined with the can 200. For example, the first electrode terminal 400 can be combined with the can 200 through the first sealing portion 210. The first sealing portion 210 can include a second combination hole 211. The terminal post 410 of the first electrode terminal 400 can be inserted into the second combination hole 211, and the first electrode terminal 400 can be combined with the first sealing portion 210. The current collecting post 310 can be inserted into the inside of the terminal post 410. Accordingly, the current collecting post 310 and the terminal post 410 of the first electrode terminal 400 can be inserted into the second combination hole 211.

[0099] The first electrode terminal 400 can include an external terminal 420 and an internal terminal 430. The external terminal 420 can be a structure located at the upper portion of the terminal post 410 and extending in the horizontal direction. The internal terminal 430 can be a structure located at the lower portion of the terminal post 410 and extending in the horizontal direction. The external terminal 420 and the internal terminal 430 can be fixed to the upper and lower faces of the first sealing portion 210, respectively, with the gasket 600 interposed therebetween. That is, the current collecting post 310, the external terminal 420, and the internal terminal 430 can be fixed to at least one face of the first sealing portion 210 with the gasket 600 interposed therebetween. In other words, the first electrode terminal 400 can be fitted to the first sealing portion 210. Here, the gasket 600 can be located between the first electrode terminal 400 and the first sealing portion 210. Due to the gasket 600, the first electrode terminal 400 and the first sealing portion 210 can not be electrically connected. However, the first electrode terminal 400 and the first sealing portion 210 can be insulated by insulating coating or the like, other than the gasket 600, and it is not necessary to include the gasket 600.

[0100] The external terminal 420 can be a structure exposed to the outside of the can 200 at the upper portion. The external terminal 420 can be electrically connected to the first electrode foil 110 and can contact an external structure to function to transfer electric power. The internal terminal 430 can be electrically connected to the first current collector 300. For example, referring to Figure 2 , the lower face of the internal terminal 430 can contact the current collecting plate 320 of the first current collector 300. Accordingly, the greater the area of the internal terminal 430, the less the resistance.

[0101] The cover portion 500 can be configured to seal the injection port 311. In a state in which the first current collector 300, the first electrode terminal 400, and the first sealing portion 210 are combined to the upper portion of the can 200, the injection port 311 can be in an open state. Electrolyte can be injected into the inside of the case through the injection port 311. After the electrolyte is injected, the injection port 311 can be sealed by the cover portion 500.

[0102] The method by which the cover portion 500 seals the injection port 311 can be various. For example, the cover portion 500 can be a rivet shape or a disc shape.

[0103] Referring to Figures 2 to 5The cap portion 500 can include a rivet shape inserted into the injection port 311. In other words, the cap portion 500 can be a rivet-shaped cap portion 500a. The rivet-shaped cap portion 500a can seal the injection port 311 by being inserted into the injection port 311 by a physical force applied.

[0104] The rivet-shaped cap portion 500a can include a rivet post 510a inserted into the injection port 311. The rivet post 510a can have various shapes. For example, it can include a cylindrical or columnar shape. The rivet post 510a can come into contact with the inner face of the current collecting post 310 by being inserted into the injection port 311. Here, in order to seal the injection port 311, the outer face of the rivet post 510a and the inner face of the current collecting post 310 can include corresponding shapes so as to engage with each other.

[0105] The rivet-shaped cap portion 500a can include a rivet head 520a located at the upper portion of the rivet post 510a and extending in the horizontal direction. Here, the upper portion of the first coupling hole 411 can include a shape corresponding to the rivet head 520a so as to be coupled with the rivet head 520a. That is, the upper portion of the first coupling hole 411 can form a wide space in the horizontal direction so as to be coupled with the rivet head 520a.

[0106] In order to provide an additional sealing force between the rivet-shaped cap portion 500a and the injection port 311, the peripheral portion of the rivet head 520a can be welded to the first electrode terminal 400. For example, the empty space that can be formed between the peripheral portion of the rivet head 520a and the external terminal 420 can be filled by welding. Alternatively, the additional sealing force can be provided by further providing the gasket 600 at the lower portion of the rivet head 520a. In the case where the gasket 600 is further provided at the lower portion of the rivet head 520a, the insertion coupling of the rivet-shaped cap portion 500a is more firm, and thus the process of welding the peripheral portion of the rivet head 520a can be omitted.

[0107] Figure 6 A cross-sectional view of a secondary battery 10 according to another embodiment is shown.

[0108] Figure 6 A secondary battery 10 using a disc-shaped cap portion 500b is shown.

[0109] The cap portion 500 can include a disc shape covering the upper portion of the injection port 311. In other words, the cap portion 500 can be a disc-shaped cap portion 500b. However, in order to seal the injection port 311, a hole can not be formed on the disc-shaped cap portion 500b.

[0110] The disc-shaped cap portion 500b can be welded in a state of covering the upper portion of the liquid injection port 311. For example, the upper portion of the first coupling hole 411 can include a shape corresponding to the disc-shaped cap portion 500b so as to be engaged therewith. The peripheral portion of the disc-shaped cap portion 500b can be welded in a state in which the disc-shaped cap portion 500b is inserted into the upper portion of the first coupling hole 411. The empty space that can be formed between the edge of the disc-shaped cap portion 500b and the external terminal 420 can be filled by welding.

[0111] Here, the jelly-roll 310 can include a protruding head 312 extending in the horizontal direction at the upper portion of one end. The protruding head 312 can include a shape that is wide in the horizontal direction, and can fill at least a portion of the upper portion of the first coupling hole 411. The disc-shaped cap portion 500b can be in contact with the protruding head 312. For example, the disc-shaped cap portion 500b can be disposed at the upper portion of the protruding head 312.

[0112] The secondary battery 10 of the present disclosure has the above-described structure, and thus is easy to assemble and weld, and thus the manufacturing process of the secondary battery can be improved. Also, without inserting a welding rod into the center of the jelly-roll type electrode assembly 100, welding is easy, and the electrode assembly 100 can be further filled with an amount of empty space corresponding to the center, and thus the energy density can be improved.

[0113] Figure 7 To illustrate a flowchart of a manufacturing method of a secondary battery 10 according to the present disclosure, Figure 8 To illustrate a flowchart of a manufacturing method of a secondary battery 10 according to the present disclosure, Figure 9 To illustrate a flowchart of a manufacturing method of a secondary battery 10 according to the present disclosure, Figure 10 To illustrate a flowchart of a manufacturing method of a secondary battery 10 according to the present disclosure, Figure 11 To illustrate a flowchart of a manufacturing method of a secondary battery 10 according to the present disclosure.

[0114] Figures 7 to 9 To illustrate a case in which the upper and lower portions of the body portion 230 are open, Figure 10 To illustrate a case in which the lower portion of the body portion 230 is open, Figure 11 To illustrate a case in which the upper portion of the body portion 230 is open.

[0115] Referring to Figures 7 to 11 and Figures 1 to 6 , the manufacturing method of the secondary battery 10 according to the present disclosure can include a second electrode welding step S100, an electrode assembly insertion step S200, a lower portion welding step S300, a first electrode welding step S400, a jelly-roll insertion step S500, an upper portion welding step S600, an injection step S700, and a sealing step S800.

[0116] First, referring to Figures 7 to 9A secondary battery manufacturing method in which the upper and lower portions of the main body 230 are open will be described. As shown in FIG. 1, the manufacturing method of the secondary battery 10 can be performed in various sequences. First, each step will be described with reference to FIG. 1, and then the sequence will be described. Figures 7 to 9 Figure 7 Figures 8 to 9

[0117] The second electrode welding step S100 can be a step of electrically connecting the second electrode foil 120 and the second sealing portion 220 of the electrode assembly 100 including the positive electrode, the negative electrode, and the separator. The method of electrical connection can be various. For example, the second electrode foil 120 and the second sealing portion 220 can be electrically connected by welding. The welding can be performed in a state in which one side of the outer side of the second electrode foil 120 is in contact with one side of the second sealing portion 220.

[0118] The electrode assembly insertion step S200 can be a step of inserting the electrode assembly 100 into the main body 230 of the can 200. The main body 230 of the can 200 can be in a state in which the upper portion or the lower portion is open. In which direction the electrode assembly 100 is inserted into the main body 230 can vary according to the sequence. For example, in a state in which the second electrode foil 120 and the second sealing portion 220 have been welded, the electrode assembly 100 can be inserted through the open lower portion of the main body 230.

[0119] The lower portion welding step S300 can be a step of welding the second sealing portion 220 and the main body 230. The second sealing portion 220 can be in a state of being combined to the main body 230. The periphery of the second sealing portion 220 can be combined to the main body 230 by welding.

[0120] The first electrode welding step S400 can be a step of electrically connecting the first electrode foil 110 and the first current collector 300 of the electrode assembly 100. The method of electrical connection can be various. For example, the first electrode foil 110 and the first sealing portion 210 can be electrically connected by welding. The welding can be performed in a state in which one side of the current collecting plate 320 of the first current collector 300 is in contact with one side of the first electrode foil 110.

[0121] The current collecting post insertion step S500 can be a step of inserting the current collecting post 310 of the first current collector 300 into the first electrode terminal 400 to electrically connect. The current collecting post 310 can be inserted into the first combination hole 411 of the first electrode terminal 400. The first combination hole 411 can be formed inside the terminal post 410. The current collecting post 310 can be in contact with the inside of the terminal post 410 by being inserted into the first combination hole 411. The outer side of the current collecting post 310 and the inside of the terminal post 410 can include corresponding shapes so as to be in contact with each other. The current collecting post 310 and the terminal post 410 can be electrically connected by being in contact with each other.

[0122] ​​​The upper welding step S600 can be a step of welding the first sealing part 210, to which the first electrode terminal 400 is inserted, to the main body part 230. The first electrode terminal 400 can be in a state of being inserted into the first sealing part 210. Specifically, the terminal post 410 of the first electrode terminal 400 can be in a state of being inserted into and coupled to the second coupling hole 211 of the first sealing part 210. Here, the first sealing part 210 can be coupled to the open upper part of the main body part 230 in the current collector insertion step S500. The peripheral portion of the first sealing part 210 coupled to the open upper part of the main body part 230 can be welded together with the main body part 230 to seal the open upper part of the main body part 230.

[0123] The injection step S700 can be a step of injecting electrolyte into the injection port 311 of the vertically penetrating manifold 310. After the upper welding step S600 and the lower welding step S300, the tank 200 can be in a sealed state except for the injection port 311. The injection step S700 can be a step of injecting electrolyte into the interior of the main body 230 through the injection port 311.

[0124] The sealing step S800 can be a step of sealing the injection port 311 using the cap 500. There can be various sealing methods. The cap 500 can also have various shapes.

[0125] For example, the cap 500 includes a shape that allows a rivet to be inserted into the injection port 311 for engagement, and the sealing step S800 can be a step of sealing by riveting the injection port 311 with the rivet-shaped cap 500a. In other words, the injection port 311 can be sealed by forcibly fastening the rivet-shaped cap 500a into the injection port 311.

[0126] Alternatively, the sealing step S800 can be a step of welding the cover 500 to the manifold 310 or the first electrode terminal 400. For example, if the cover 500 is a disc-shaped cover 500b including a disc shape, the cover 500 can be welded to the manifold 310 or the first electrode terminal 400 to seal the injection port 311 while covering the upper part of the injection port 311. Alternatively, the rivet head 520a of the rivet-shaped cover 500a can be welded to the manifold 310 or the first electrode terminal 400 to seal the injection port 311 while the rivet-shaped cover 500a is embedded and joined to the injection port 311.

[0127] like Figures 8 to 9 As shown, the manufacturing sequence of the secondary battery 10 can be changed in various ways. For example, refer to... Figure 8The first electrode welding step S400, the current collector post insertion step S500, the electrode assembly insertion step S200, the upper welding step S600, the second electrode welding step S100, the lower welding step S300, the injection step S700, and the sealing step S800 can be performed in this order. Thus, the current collector post 310 can be inserted into the first electrode terminal 400 after the first electrode foil 110 is welded with the first current collector 300. Then, the electrode assembly 100 in which the first current collector 300, the first electrode terminal 400, and the first sealing portion 210 are combined can be inserted into the main body portion 230, and then the first sealing portion 210 can be welded with the main body portion 230. The second electrode foil 120 can be welded with the second sealing portion 220 and the lower portion of the main body portion 230 can be welded after the upper portion of the main body portion 230 is completed.

[0128] Alternatively, as shown in FIG. 7, the first electrode welding step S400, the electrode assembly insertion step S200, the second electrode welding step S100, the lower welding step S300, the current collector post insertion step S500, the upper welding step S600, the injection step S700, and the sealing step S800 can be performed in this order. Figure 9

[0129] Referring to FIG. 6, a secondary battery manufacturing method in which the main body portion 230 is open at the lower portion will be described. In the case where the main body portion 230 is open at the lower portion and closed at the upper portion, the first sealing portion 210 is in a state of being integrated with the main body portion 230, and the second sealing portion 220 can be combined with the main body portion 230 in a separated state. Figure 10 Here, the secondary battery manufacturing method can omit the upper welding step S600. Thus, the secondary battery manufacturing method can include the first electrode welding step S400, the electrode assembly insertion step S200, the current collector post insertion step S500, the second electrode welding step S100, the lower welding step S300, the injection step S700, and the sealing step S800.

[0130] Referring to FIG. 7, a secondary battery manufacturing method in which the main body portion 230 is open at the upper portion will be described. In the case where the main body portion 230 is open at the upper portion and closed at the lower portion, the second sealing portion 220 is in a state of being integrated with the main body portion 230, and the first sealing portion 210 can be combined with the main body portion 230 in a separated state.

[0131] Figure 11 Here, the secondary battery manufacturing method can omit the lower welding step S300. Thus, the secondary battery manufacturing method can include the first electrode welding step S400, the electrode assembly insertion step S200, the second electrode welding step S100, the current collector post insertion step S500, the upper welding step S600, the injection step S700, and the sealing step S800.

[0132] Here, the secondary battery manufacturing method can omit the lower welding step S300. Thus, the secondary battery manufacturing method can include the first electrode welding step S400, the electrode assembly insertion step S200, the second electrode welding step S100, the current collector post insertion step S500, the upper welding step S600, the injection step S700, and the sealing step S800. ​​

[0133] That is, if both the upper portion and the lower portion of the main body 230 are open, the upper welding step S600 and the lower welding step S300 can be included, and if either of the upper portion and the lower portion of the main body 230 is open, either of the upper welding step S600 and the lower welding step S300 can be omitted.

[0134] Figures 7 to 11 The manufacturing method of the secondary battery 10 according to the present disclosure is sequentially shown, but is not necessarily limited thereto. Thus, it can be manufactured in various sequences other than the sequence described in the present disclosure.

[0135] Further, the cylindrical shape described in the present disclosure is a level that can be appropriately changed, and thus is not limited to the above shape. The welding method is also not limited thereto, and other joining methods can be used within an appropriately changed range.

[0136] The embodiments of the present disclosure are described in detail above, but the technical solutions of the present disclosure are not limited thereto, and various modifications and changes can be made within the scope of the technical solutions described in the present disclosure without departing from the technical ideas of the present disclosure, which is obvious to those skilled in the art.

Claims

1. A secondary battery characterized by comprising: Comprising: an electrode assembly including a positive electrode, a negative electrode, and a separator; a can containing the electrode assembly; a first current collector electrically connected to the electrode assembly, including a current collecting post protruding upward, and a liquid injection port penetrating the current collecting post upward and downward; a first electrode terminal electrically connected to the first current collector, combined with the can; and a cap portion configured to seal the liquid injection port.

2. The secondary battery according to claim 1, characterized in that: the first current collector includes a disk-shaped current collecting plate disposed at an upper portion of the electrode assembly and providing the current collecting post.

3. The secondary battery according to claim 1 or 2, characterized in that: the first electrode terminal includes a terminal post in contact with the current collecting post to be electrically connected.

4. The secondary battery according to claim 3, characterized by the first electrode terminal further includes: an outer terminal located at an upper portion of the terminal post and extending in a horizontal direction; and an inner terminal located at a lower portion of the terminal post and extending in a horizontal direction.

5. The secondary battery according to claim 3, characterized in that: the current collecting post is in contact with an inner side of the terminal post to be electrically connected.

6. The secondary battery according to claim 1 or 2, characterized by the can includes: a main body portion of which at least one of an upper portion and a lower portion is open; a first sealing portion sealing the upper portion of the main body portion; and a second sealing portion sealing the lower portion of the main body portion.

7. The secondary battery according to claim 6, characterized in that: at least one of the first sealing portion and the second sealing portion is integrated with the main body portion.

8. The secondary battery according to claim 6, characterized in that: the first electrode terminal is combined with the can through the first sealing portion.

9. The secondary battery according to claim 1 or 2, characterized in that: the cap portion includes a rivet shape that is embeddedly combined by being inserted into the liquid injection port.

10. The secondary battery according to claim 9, characterized by the cap portion includes: a rivet post inserted into the liquid injection port; and a rivet head located at an upper portion of the rivet post and extending in a horizontal direction.

11. The secondary battery according to claim 10, characterized in that: an upper portion of the first electrode terminal includes a shape corresponding to the rivet head for being combined with the rivet head.

12. The secondary battery according to claim 1 or 2, characterized in that: the cap portion includes a disk shape that covers an upper portion of the liquid injection port.

13. The secondary battery according to claim 12, characterized in that: the current collecting post includes a protruding head extending in a horizontal direction at one end of an upper portion, the cap portion is in contact with the protruding head.

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