WO2018199438A1 - Secondary battery - Google Patents

Secondary battery Download PDF

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Publication number
WO2018199438A1
WO2018199438A1 PCT/KR2018/001064 KR2018001064W WO2018199438A1 WO 2018199438 A1 WO2018199438 A1 WO 2018199438A1 KR 2018001064 W KR2018001064 W KR 2018001064W WO 2018199438 A1 WO2018199438 A1 WO 2018199438A1
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WO
WIPO (PCT)
Prior art keywords
electrode
terminal
connection
secondary battery
cap plate
Prior art date
Application number
PCT/KR2018/001064
Other languages
French (fr)
Korean (ko)
Inventor
장명재
곽승호
변상원
Original Assignee
삼성에스디아이(주)
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 삼성에스디아이(주) filed Critical 삼성에스디아이(주)
Publication of WO2018199438A1 publication Critical patent/WO2018199438A1/en

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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/50—Current conducting connections for cells or batteries
    • H01M50/572—Means for preventing undesired use or discharge
    • H01M50/584—Means for preventing undesired use or discharge for preventing incorrect connections inside or outside the batteries
    • H01M50/586—Means for preventing undesired use or discharge for preventing incorrect connections inside or outside the batteries inside the batteries, e.g. incorrect connections of electrodes
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/10—Primary casings; Jackets or wrappings
    • H01M50/147—Lids or covers
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/10—Primary casings; Jackets or wrappings
    • H01M50/147—Lids or covers
    • H01M50/148—Lids or covers characterised by their shape
    • H01M50/15—Lids or covers characterised by their shape for prismatic or rectangular cells
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/10—Primary casings; Jackets or wrappings
    • H01M50/172—Arrangements of electric connectors penetrating the casing
    • H01M50/174—Arrangements of electric connectors penetrating the casing adapted for the shape of the cells
    • H01M50/176—Arrangements of electric connectors penetrating the casing adapted for the shape of the cells for prismatic or rectangular cells
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/30—Arrangements for facilitating escape of gases
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/30—Arrangements for facilitating escape of gases
    • H01M50/342—Non-re-sealable arrangements
    • H01M50/3425—Non-re-sealable arrangements in the form of rupturable membranes or weakened parts, e.g. pierced with the aid of a sharp member
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/50—Current conducting connections for cells or batteries
    • H01M50/531—Electrode connections inside a battery casing
    • H01M50/533—Electrode connections inside a battery casing characterised by the shape of the leads or tabs
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/50—Current conducting connections for cells or batteries
    • H01M50/572—Means for preventing undesired use or discharge
    • H01M50/574—Devices or arrangements for the interruption of current
    • H01M50/578—Devices or arrangements for the interruption of current in response to pressure
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/50—Current conducting connections for cells or batteries
    • H01M50/572—Means for preventing undesired use or discharge
    • H01M50/584—Means for preventing undesired use or discharge for preventing incorrect connections inside or outside the batteries
    • H01M50/59—Means for preventing undesired use or discharge for preventing incorrect connections inside or outside the batteries characterised by the protection means
    • H01M50/593—Spacers; Insulating plates
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10—Energy storage using batteries

Definitions

  • the present invention relates to a secondary battery.
  • a secondary battery is a battery that can be charged and discharged unlike a primary battery that cannot be charged.
  • a secondary battery is used in portable electronic devices such as mobile phones and camcorders. Large capacity batteries with dozens of cells connected are used as motor power sources for electric bicycles, electric scooters, hybrid cars, and electric cars.
  • Secondary batteries are manufactured in various shapes, and typical shapes include square, cylindrical, and pouch types, and an electrode assembly formed between a positive electrode and a negative electrode through a separator, which is an insulator, and an electrolyte together in a case. It is configured to receive and install a cap plate in the case. In addition, an electrode terminal is electrically connected to the electrode assembly, which is exposed or protruded to the outside through the cap plate.
  • the present invention provides a secondary battery capable of improving the welding quality between the safety vent and the connection tab.
  • a secondary battery includes an electrode assembly including a first electrode, a second electrode, and a separator interposed between the first electrode and the second electrode; A case accommodating the electrode assembly; A cap plate coupled to an upper portion of the case and electrically connected to the first electrode, and having a safety vent formed at one side thereof; A first electrode terminal formed through the cap plate; And a connection tab for electrically connecting the first electrode terminal and the safety vent, wherein a coupling protrusion is formed at the center of the safety vent, and a coupling hole is formed at the connection tab, to which the coupling protrusion is coupled. do.
  • connection tab and the safety vent may be electrically connected by welding the joint surface of the coupling protrusion and the coupling hole.
  • the safety vent is fixed to the cap plate; A break portion located inside the fixing portion and having a notch formed therein; An inverting part disposed inside the breaking part and formed of a inverting plate concave from the cap plate; And a coupling part disposed above the inversion part and formed thicker than a thickness of the inversion part, and to which the connection tab is coupled.
  • the coupling protrusion may be formed on an upper portion of the coupling portion.
  • connection tab may include a terminal connection part electrically connected to the first electrode terminal; A vent connection electrically connected to the safety vent; And a connection part connecting the terminal connection part and the vent connection part and formed to be inclined.
  • the coupling hole may be formed in the vent connection portion.
  • a notch may be formed in the terminal connection portion.
  • the display device may further include a first terminal plate coupled to the first electrode terminal protruding to an upper portion of the cap plate, and the first terminal plate may have a stepped portion to which the connection tab is coupled.
  • a first collector plate electrically connected to the first electrode wherein the first collector plate comprises: a first connection part connected to a first electrode uncoated part; And a first extension part bent at an upper end of the first connection part and formed in parallel with the cap plate, and one end of the first extension part may protrude upward to form a protrusion electrically connected to the cap plate.
  • a lower insulating member may be formed between the first electrode terminal and the first extension part.
  • a secondary battery according to an embodiment of the present invention includes a safety vent having a coupling protrusion and a connection tab having a coupling hole coupled to the coupling protrusion, and welding the coupling surface between the coupling protrusion and the coupling hole by butt welding. It will be possible to improve. Therefore, the secondary battery according to the present invention can reduce the welding defect, reduce the production cost and improve the reliability of the product.
  • FIG. 1 is a perspective view illustrating a rechargeable battery according to an exemplary embodiment of the present invention.
  • FIG. 2 is a cross-sectional view illustrating a rechargeable battery taken along the line II ′ of FIG. 1.
  • FIG 3 is an enlarged cross-sectional view illustrating a safety vent in a rechargeable battery according to an exemplary embodiment of the present invention.
  • FIG. 4 is a perspective view of a safety vent according to an embodiment of the present invention.
  • FIG. 5 is a cross-sectional view of a safety vent according to an embodiment of the present invention.
  • connection tab 6 is a plan view of a connection tab according to an embodiment of the present invention.
  • FIG. 7 and 8 are cross-sectional views illustrating an operating state of a safety vent in a rechargeable battery according to an exemplary embodiment of the present invention.
  • terms relating to spaces such as “beneath”, “below”, “lower”, “above”, and “upper” may be referred to as an element or Used for easy understanding of the feature and other elements or features. Terms related to this space are for easy understanding of the present invention according to various manufacturing processes or use conditions of the secondary battery, and are not intended to limit the present invention. For example, when the secondary battery of the figure is turned upside down, the element described as “lower” or “below” becomes “top” or “above.” Thus, “bottom” encompasses “top” or “bottom”.
  • FIG. 1 is a perspective view illustrating a rechargeable battery according to an exemplary embodiment of the present invention.
  • FIG. 2 is a cross-sectional view illustrating a rechargeable battery taken along the line II ′ of FIG. 1.
  • 3 is an enlarged cross-sectional view illustrating a safety vent in a rechargeable battery according to an exemplary embodiment of the present invention.
  • 4 is a perspective view of a safety vent according to an embodiment of the present invention.
  • 5 is a cross-sectional view of a safety vent according to an embodiment of the present invention.
  • 6 is a plan view of a connection tab according to an embodiment of the present invention.
  • a secondary battery 100 may include an electrode assembly 110, a first current collecting plate 120, a second current collecting plate 130, and a first electrode terminal ( 140, a second electrode terminal 150, a case 160, a cap assembly 170, a safety vent 180, and a connection tab 190.
  • the electrode assembly 110 includes a first electrode 111, a second electrode 112, and a separator 113 interposed between the first electrode 111 and the second electrode 112.
  • the electrode assembly 110 may be formed by winding a laminate of the first electrode 111, the separator 113, and the second electrode 112 in a jelly-roll form.
  • the first electrode 111 may act as an anode
  • the second electrode 112 may act as a cathode.
  • the first electrode 111 is formed by applying a first electrode active material such as transition metal oxide to a first electrode current collector formed of a metal foil such as aluminum, and the first electrode uncoated portion is an area where the first active material is not coated. (111a).
  • the first electrode uncoated portion 111a serves as a passage for current flow between the first electrode 111 and the outside of the first electrode.
  • the second electrode 112 is formed by applying a second electrode active material such as graphite or carbon to a second electrode current collector formed of a metal foil such as copper or nickel, and is a region in which the second active material is not coated. And the non-coated portion 112a.
  • the second electrode uncoated portion 112a serves as a passage for current flow between the second electrode 112 and the outside of the second electrode.
  • the separator 113 is positioned between the first electrode 111 and the second electrode 112 to prevent a short and to allow movement of lithium ions.
  • the separator 113 may be made of polyethylene, polypropylene, or a composite film of polyethylene and polypropylene.
  • the first collector plate 120 is formed of a conductive material such as aluminum, and is in contact with the first electrode uncoated portion 111a protruding to one end of the electrode assembly 110, thereby electrically contacting the first electrode 111. Is connected.
  • the first current collecting plate 120 includes a first connection part 121 and a first extension part 122.
  • the first connection portion 121 is formed on one side of the electrode assembly 110, and is formed in a plate shape substantially in contact with the first electrode uncoated portion 111a.
  • the first connection portion 121 may be welded to the first electrode uncoated portion 111a.
  • the first extension part 122 is bent at an upper end of the first connection part 121 to extend along a lower portion of the cap plate 171 to be described later.
  • the first extension part 122 is formed in a direction perpendicular to the first connection part 121 and is formed in parallel with the cap plate 171.
  • a protrusion 123 is formed at one end of the first extension part 122, and the protrusion 123 is electrically connected to a lower portion of the cap plate 171.
  • the protrusion 123 may be welded to the cap plate 171 by ultrasonic welding, electric welding, arc welding, or the like. Accordingly, the cap plate 171 is electrically connected to the first electrode 111.
  • the second collector plate 130 is made of a conductive material such as nickel, and is in contact with the second electrode uncoated portion 112a protruding to the other end of the electrode assembly 110, thereby electrically contacting the second electrode 112. Connected.
  • the second collector plate 130 includes a second connection part 131 and a second extension part 132.
  • the second connection portion 131 is formed on the other side of the electrode assembly 110, and is formed in a plate shape substantially in contact with the second electrode uncoated portion 112a.
  • the second connection portion 131 may be welded to the second electrode uncoated portion 112a.
  • the second extension part 132 is bent at an upper end of the second connection part 131 to extend along a lower portion of the cap plate 171.
  • the second extension part 132 is formed in a direction perpendicular to the second connection part 131 and is formed parallel to the cap plate 171.
  • a terminal hole 133 is formed in the second extension part 132, and the second electrode terminal 150 is fitted into the terminal hole 133.
  • the first electrode terminal 140 is formed of a conductive material such as aluminum, and is coupled to the first current collector 120 to be electrically connected to the first electrode 111.
  • the first electrode terminal 140 includes a first terminal body 141 and a first terminal extension 142.
  • the first terminal body 141 passes through the cap plate 171, and an upper portion thereof is riveted to be fixed to the cap plate 171.
  • the first terminal extension part 142 extends in the horizontal direction from the bottom of the first terminal body 141 to be in close contact with the bottom surface of the cap plate 171. The first terminal extension 142 prevents the first terminal body 141 from coming off the cap plate 171.
  • the second electrode terminal 150 is formed of a conductive material such as nickel, and is electrically connected to the second electrode 112 by being combined with the second current collecting plate 130.
  • the second electrode terminal 150 includes a second terminal body 151 and a second terminal extension 152.
  • the second terminal body 151 penetrates through the cap plate 171, and an upper portion thereof is riveted to be fixed to the cap plate 171.
  • the second terminal extension part 152 extends in the horizontal direction from the bottom of the second terminal body 151 to be in close contact with the bottom surface of the cap plate 171.
  • the second terminal extension 152 prevents the second terminal body 151 from coming off the cap plate 151. Meanwhile, a portion of the second terminal body 151 connected to the lower portion of the terminal extension part 152 is inserted into the terminal hole 133 of the second current collecting plate 130 and electrically coupled thereto.
  • the case 160 is formed of a conductive metal such as aluminum, an aluminum alloy, or nickel plated steel, and includes an electrode assembly 110, a first current collector 120, a second current collector 130, and a first electrode terminal.
  • the 140 and the second electrode terminal 150 may have a substantially hexahedral shape in which an opening to which the second electrode terminal 150 is inserted and formed is formed.
  • the case 160 may act as one polarity, for example, an anode.
  • the cap assembly 170 is coupled to the top of the case 160.
  • the cap assembly 170 may include a cap plate 171, a stopper 172, a gasket 173, a first terminal plate 174, a second terminal plate 175, an upper insulating member 176, and a lower portion. Insulation member 177 is included.
  • the cap plate 171 seals the opening of the case 160 and may be formed of the same material as the case 160.
  • the cap plate 171 may be coupled to the case 160 by laser welding.
  • the cap plate 171 may have the same polarity as the case 160.
  • the cap plate 171 is formed with an electrolyte injection hole 171a for injecting an electrolyte and a vent hole 171b in which a safety vent 180 is formed.
  • the vent hole 171b may have a stepped surface 171c to couple the safety vent 180 relatively thinner than the thickness of the cap plate 171.
  • the electrolyte injection hole 171a is sealed with a stopper 172.
  • the gasket 173 is formed of an insulating material between each of the first electrode terminal 140 and the second electrode terminal 150 and the cap plate 171 to form the first electrode terminal 140 and the second electrode terminal 150. Seal between each and the cap plate 171. In addition, the gasket 173 is coupled between each of the first electrode terminal 140 and the second electrode terminal 150 and the cap plate 171 at the bottom of the cap plate 171. The gasket 173 prevents external moisture from penetrating the inside of the secondary battery 100 or prevents the electrolyte solution contained in the secondary battery 100 from flowing out.
  • the first terminal plate 174 and the second terminal plate 175 are coupled to each of the first electrode terminal 140 and the second electrode terminal 150.
  • the upper portions of the first and second electrode terminals 140 and 150 are riveted, respectively.
  • the first and second electrode terminals 140 and 150 are fixed to the first and second terminal plates 174 and 175.
  • the connection tab 190 to be described later is coupled to the first terminal plate 174. Therefore, the first terminal plate 174 is formed with a stepped portion 174a to which the connection tab 190 is coupled.
  • the upper insulating member 176 is positioned between the first and second terminal plates 174 and 175 and the cap plate 171 so that the first electrode terminal 140 and the second electrode terminal 150 are fitted therein, respectively. Is formed.
  • the upper insulating member 176 is in close contact with the cap plate 171 and the gasket 173 through the first and second terminal plates 174 and 175.
  • the upper insulating member 176 insulates the first electrode terminal 140 and the second electrode terminal 150 from the cap plate 171.
  • the lower insulating member 177 is formed between each of the first current collector plate 120 and the second current collector plate 130 and the cap plate 171, and thus the first current collector plate 120 and the second current collector plate 130. The occurrence of unnecessary short circuit between each and the cap plate 171 is prevented.
  • the lower insulating member 177 is formed between the first extension part 122 of the first current collecting plate 120 and the cap plate 171.
  • the lower insulating member 177 is positioned between the first terminal extension part 142 of the first electrode terminal 140 and the first extension part 122 of the first current collecting plate 120. Therefore, the first electrode terminal 140 does not directly contact the first current collecting plate 120 by the lower insulating member 177.
  • the lower insulating member 177 is formed between the second extension part 132 of the second current collecting plate 130 and the cap plate 171.
  • the safety vent 180 is coupled to the vent hole 171b of the cap plate 171. Specifically, the safety vent 180 is coupled across the stepped surface 171c of the vent hole 171b to seal the vent hole 171b.
  • the safety vent 180 is formed of the same material as the cap plate 171 and is electrically connected to the cap plate 171. In addition, the safety vent 180 breaks when the internal pressure of the secondary battery 100 reaches a set breaking pressure due to overcharging or overdischarging, so that the vent hole 171b is opened, and thus the secondary battery 100 is opened. Prevent explosion.
  • the safety vent 180 may include a fixing part 181, a breaking part 182, an inverting part 183, and a coupling part 184.
  • the fixing part 181 is an edge portion of the safety vent 180 and is coupled to the stepped surface 171c of the vent hole 171b.
  • the fixing part 181 may be fixed to the step surface 171c by welding.
  • the breaking part 182 is positioned inside the fixing part 181 and is broken when the internal pressure of the secondary battery 100 is higher than the set breaking pressure. Therefore, the notch 182a is formed on the lower surface of the breaker 182, so that the safety vent 180 may be easily broken.
  • the breaking pressure of the safety vent 180 may be set to the thickness and shape of the breaking part 182 and the concave degree of the inverting part 183.
  • the inverting portion 183 is positioned inside the breaker 182, that is, at the center of the safety vent 180, and is formed to be convex toward the inside of the case 160.
  • the inverting portion 183 is formed of a reversing plate formed concave than the surface of the cap plate 171. Therefore, when the internal pressure of the secondary battery 100 is higher than the set reference pressure, the inverting portion 183 is inverted to be convex upward. In addition, when the internal pressure of the secondary battery 100 is higher than the breaking pressure, the breaking part 182 is broken.
  • a coupling portion 184 having a relatively thick thickness is formed on the upper portion of the inverting portion 183 compared to the thickness of the safety vent 180.
  • a connection tab 190 is coupled to the coupling portion 184 to electrically connect the first electrode terminal 120 to the first electrode 111. Since the coupling part 184 is welded with the connection tab 190, the coupling part 184 has a thickness such that the safety vent 180 is not damaged when the coupling part 184 and the connection tab 190 are welded.
  • a coupling protrusion 184a is formed at an upper portion of the coupling portion 184. The connection tab 190 is fitted to the coupling protrusion 184a, and a joint surface of the coupling protrusion 184a and the connection tab 190 is welded.
  • the thickness of the coupling protrusion 184a protrudes from the thickness of the connection tab 190. Therefore, the connection tab 190 coupled to the coupling protrusion 184a forms the same plane as the upper surface of the coupling protrusion 184a.
  • connection tab 190 is connected between the first terminal plate 174 and the safety vent 180 to electrically connect the first terminal plate 174 and the safety vent 180. Accordingly, the connection tab 190 electrically connects the first electrode terminal 120 to the first electrode 111. Specifically, the first electrode terminal 120 is connected to the first electrode through the first terminal plate 174, the connection tab 190, the safety vent 180, the cap plate 171, and the first current collecting plate 120. 111) is electrically connected.
  • the connection tab 190 may include a terminal connection part 191 electrically connected to the first terminal plate 174, a vent connection part 192 electrically connected to the safety vent 180, and the terminal connection part 191. And a connecting portion 193 for electrically connecting the vent connecting portion 192.
  • the connection tab 190 may be formed of a metal such as aluminum or an aluminum alloy.
  • the terminal connecting portion 191 has a substantially rectangular plate shape, one end of which is electrically connected to the stepped portion 174a of the first terminal plate 174.
  • the terminal connecting portion 191 may be welded to the terminal portion 174a by ultrasonic welding, resistance welding, spot welding, or the like.
  • the vent connection 192 is coupled to and electrically connected to the coupling part 184 of the safety vent 180.
  • a coupling hole 192a is formed in the vent connection part 192, and a coupling protrusion 184a of the coupling part 184 is coupled to the coupling hole 192a.
  • the upper surface of the vent connecting portion 192 and the coupling protrusion 184a forms the same plane. At this time, when the joining surface of the joining protrusion 184a and the joining hole 192a is welded, a part of the joining protrusion 184a and the joining hole 192a around the joining surface are melted and melted.
  • the mechanical coupling strength between the safety vent 180 and the connection tab 190 is improved, and this welding method is called butt welding.
  • Such butt welding improves the welding quality of the coupling part 184 and the connection tab 190.
  • the overlapping welding for placing the connection tab on the upper part of the coupling part and welding the upper part of the connection tab and the lower part of the coupling part is performed, but the overlapping welding tends to have a relatively high defect rate. Therefore, in the present invention, the coupling hole 192a is formed in the connection tab 190 and the coupling protrusion 184a is formed in the safety vent 180, and the coupling protrusion 184a is coupled to the coupling hole 192a. By welding the joint surface, the welding quality can be improved.
  • connection part 193 connects the terminal connection part 191 and the vent connection part 192 and is formed to be inclined. Because the first terminal plate 174 to which the terminal connecting portion 191 is coupled is formed to protrude from the cap plate 171 to have a relatively high height, and the safety vent 180 to which the vent connecting portion 192 is coupled. Is because it is formed concave from the cap plate 171 and the height is relatively low. In addition, the notch 193a is formed at the connection portion 193, and when the safety vent 180 is broken, the connection tab 190 may be broken together.
  • the secondary battery 100 has a safety vent 180 having a coupling protrusion 184a and a connection tab 190 having a coupling hole 192a coupled to the coupling protrusion 184a. ), And by butt welding the coupling surface between the coupling protrusion 184a and the coupling hole 192a, the welding quality can be improved. Therefore, the secondary battery 100 according to the present invention can reduce the welding defect, reduce the production cost and improve the reliability of the product.
  • FIGS. 7 and 8 are cross-sectional views illustrating an operating state of a safety vent in a rechargeable battery according to an exemplary embodiment of the present invention. Referring to FIGS. 7 and 8, a method of operating a safety vent in a rechargeable battery according to an exemplary embodiment will be described.
  • the inverting portion 183 of the safety vent 180 is inverted to be convex upward.
  • the vent connection unit 192 of the connection tab 190 rises upward and the connection unit 193 is formed to be substantially flat.
  • the breaking part 182 of the safety vent 180 is broken to open the vent hole 171b.
  • the notch 182a is formed in the break portion 182, break is easy.
  • the connection tab 190 may be broken together by the notch 193a formed in the connection unit 193.
  • the safety vent 180 is broken, the electrical connection between the cap plate 171 and the first terminal plate 174 is broken, so that the electrical connection between the first electrode terminal 120 and the first electrode 111 is lost. The connection will be lost. Therefore, the current of the secondary battery 100 is cut off.

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  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • General Chemical & Material Sciences (AREA)
  • Gas Exhaust Devices For Batteries (AREA)
  • Connection Of Batteries Or Terminals (AREA)

Abstract

The present invention relates to a secondary battery capable of improving welding quality between a safety vent and a connection tab. For example, disclosed is a secondary battery comprising: an electrode assembly including a first electrode, a second electrode, and a separator interposed between the first electrode and the second electrode; a case for accommodating the electrode assembly; a cap plate coupled to the upper portion of the case, electrically connected to the first electrode, and having a safety vent formed on one side thereof; a first electrode terminal formed to pass through the cap plate; and a connection tab for electrically connecting the first electrode terminal to the safety vent, wherein a coupling protrusion is formed in the center of the safety vent, and a coupling hole to which the coupling protrusion is coupled is formed in the connection tab.

Description

이차 전지Secondary battery
본 발명은 이차 전지에 관한 것이다.The present invention relates to a secondary battery.
일반적으로 이차 전지는 충전이 불가능한 일차 전지와는 달리 충전 및 방전이 가능한 전지로서, 하나의 배터리 셀이 팩 형태로 포장된 저용량 전지의 경우 휴대폰 및 캠코더와 같은 휴대가 가능한 소형 전자기기에 사용되고, 배터리 셀이 수십 개 연결된 대용량 전지의 경우 전기 자전거, 전기 스쿠터, 하이브리드 자동차, 전기 자동차 등의 모터 구동용 전원으로 사용되고 있다.In general, a secondary battery is a battery that can be charged and discharged unlike a primary battery that cannot be charged. In the case of a low-capacity battery in which one battery cell is packed in a pack form, a secondary battery is used in portable electronic devices such as mobile phones and camcorders. Large capacity batteries with dozens of cells connected are used as motor power sources for electric bicycles, electric scooters, hybrid cars, and electric cars.
이차 전지는 여러 가지 형상으로 제조되고 있는데 대표적인 형상으로는 각형, 원통형 및 파우치형 등을 들 수 있으며, 양극판 및 음극판 사이에 절연체인 세퍼레이터(separator)를 개재하여 형성된 전극 조립체와, 전해액을 함께 케이스에 수용하고, 케이스에 캡 플레이트를 설치하여 구성된다. 또한, 상기 전극 조립체에는 전극 단자가 전기적으로 연결되며, 이는 상기 캡 플레이트를 통하여 외부로 노출 또는 돌출된다.Secondary batteries are manufactured in various shapes, and typical shapes include square, cylindrical, and pouch types, and an electrode assembly formed between a positive electrode and a negative electrode through a separator, which is an insulator, and an electrolyte together in a case. It is configured to receive and install a cap plate in the case. In addition, an electrode terminal is electrically connected to the electrode assembly, which is exposed or protruded to the outside through the cap plate.
한편, 이차 전지는 전력소모가 너무 많거나 충전 전류가 너무 큰 경우, 배터리 셀 내 극심한 온도 상승으로 인해 내부에 압력이 상승되어 폭발할 수 있다. 따라서, 이차 전지의 내부압력에 따라 파단되는 안전 벤트를 구비하여 이차 전지의 폭발을 방지할 수 있다.On the other hand, when the secondary battery consumes too much power or the charging current is too large, the internal battery may explode due to an increase in pressure due to an extreme temperature increase in the battery cell. Therefore, a safety vent that breaks according to the internal pressure of the secondary battery may be provided to prevent explosion of the secondary battery.
본 발명은 안전 벤트와 연결탭 사이의 용접 품질을 향상시킬 수 있는 이차 전지를 제공한다.The present invention provides a secondary battery capable of improving the welding quality between the safety vent and the connection tab.
본 발명에 의한 이차 전지는 제 1 전극, 제 2 전극 및 상기 제 1 전극과 제 2 전극 사이에 개재된 세퍼레이터를 포함하는 전극 조립체; 상기 전극 조립체를 수용하는 케이스; 상기 케이스의 상부에 결합되고 상기 제 1 전극과 전기적으로 연결되며, 일측에 안전 벤트가 형성된 캡 플레이트; 상기 캡 플레이트를 관통하여 형성된 제 1 전극 단자; 및 상기 제 1 전극 단자와 상기 안전 벤트를 전기적으로 연결하는 연결탭을 포함하고, 상기 안전 벤트의 중심에는 결합 돌기가 형성되고, 상기 연결탭에는 상기 결합 돌기가 결합되는 결합홀이 형성된 것을 특징으로 한다.A secondary battery according to the present invention includes an electrode assembly including a first electrode, a second electrode, and a separator interposed between the first electrode and the second electrode; A case accommodating the electrode assembly; A cap plate coupled to an upper portion of the case and electrically connected to the first electrode, and having a safety vent formed at one side thereof; A first electrode terminal formed through the cap plate; And a connection tab for electrically connecting the first electrode terminal and the safety vent, wherein a coupling protrusion is formed at the center of the safety vent, and a coupling hole is formed at the connection tab, to which the coupling protrusion is coupled. do.
상기 결합 돌기와 상기 결합홀의 접합면을 용접하여, 상기 연결탭과 상기 안전 벤트가 전기적으로 연결될 수 있다.The connection tab and the safety vent may be electrically connected by welding the joint surface of the coupling protrusion and the coupling hole.
상기 안전 벤트는 상기 캡 플레이트에 고정되는 고정부; 상기 고정부의 내측에 위치하고, 노치가 형성된 파단부; 상기 파단부의 내측에 위치하고, 상기 캡 플레이트로부터 오목하게 형성된 반전 플레이트로 이루어진 반전부; 및 상기 반전부의 상부에 위치하고 상기 반전부의 두께보다 두껍게 형성되며, 상기 연결탭이 결합되는 결합부;를 포함할 수 있다.The safety vent is fixed to the cap plate; A break portion located inside the fixing portion and having a notch formed therein; An inverting part disposed inside the breaking part and formed of a inverting plate concave from the cap plate; And a coupling part disposed above the inversion part and formed thicker than a thickness of the inversion part, and to which the connection tab is coupled.
상기 결합 돌기는 상기 결합부의 상부에 형성될 수 있다.The coupling protrusion may be formed on an upper portion of the coupling portion.
상기 연결탭은 상기 제 1 전극 단자에 전기적으로 연결되는 단자 접속부; 상기 안전 벤트에 전기적으로 연결되는 벤트 접속부; 및 상기 단자 접속부와 상기 벤트 접속부를 연결하며, 경사지게 형성된 연결부;를 포함할 수 있다.The connection tab may include a terminal connection part electrically connected to the first electrode terminal; A vent connection electrically connected to the safety vent; And a connection part connecting the terminal connection part and the vent connection part and formed to be inclined.
상기 결합홀은 상기 벤트 접속부에 형성될 수 있다.The coupling hole may be formed in the vent connection portion.
상기 단자 접속부에는 노치가 형성될 수 있다.A notch may be formed in the terminal connection portion.
상기 캡 플레이트의 상부로 돌출된 상기 제 1 전극 단자에 결합된 제 1 단자 플레이트를 더 포함하고, 상기 제 1 단자 플레이트에는 상기 연결탭이 결합되는 단차부가 형성될 수 있다.The display device may further include a first terminal plate coupled to the first electrode terminal protruding to an upper portion of the cap plate, and the first terminal plate may have a stepped portion to which the connection tab is coupled.
상기 제 1 전극과 전기적으로 연결된 제 1 집전판을 더 포함하고, 상기 제 1 집전판은 제 1 전극 무지부와 연결된 제 1 연결부; 및 상기 제 1 연결부의 상단에서 절곡되어 상기 캡 플레이트와 평행하게 형성된 제 1 연장부를 포함하고, 상기 제 1 연장부의 일단에는 상부로 돌출되어 상기 캡 플레이트와 전기적으로 연결된 돌출부가 형성될 수 있다.A first collector plate electrically connected to the first electrode, wherein the first collector plate comprises: a first connection part connected to a first electrode uncoated part; And a first extension part bent at an upper end of the first connection part and formed in parallel with the cap plate, and one end of the first extension part may protrude upward to form a protrusion electrically connected to the cap plate.
상기 제 1 전극 단자와 상기 제 1 연장부 사이에는 하부 절연부재가 형성될 수 있다.A lower insulating member may be formed between the first electrode terminal and the first extension part.
본 발명의 일 실시예에 따른 이차 전지는 결합 돌기를 갖는 안전 벤트와 상기 결합 돌기에 결합되는 결합홀을 갖는 연결탭을 구비하고, 상기 결합 돌기와 결합홀 사이의 결합면을 맞대기 용접함으로써, 용접 품질을 향상시킬 수 있게 된다. 따라서, 본 발명에 따른 이차 전지는 용접 불량을 줄여, 생산 비용을 절감하며 제품의 신뢰성을 향상시킬 수 있게 된다.A secondary battery according to an embodiment of the present invention includes a safety vent having a coupling protrusion and a connection tab having a coupling hole coupled to the coupling protrusion, and welding the coupling surface between the coupling protrusion and the coupling hole by butt welding. It will be possible to improve. Therefore, the secondary battery according to the present invention can reduce the welding defect, reduce the production cost and improve the reliability of the product.
도 1은 본 발명의 일 실시예에 따른 이차 전지를 도시한 사시도이다. 1 is a perspective view illustrating a rechargeable battery according to an exemplary embodiment of the present invention.
도 2는 도 1의 I-I' 선을 따라 절취한 이차 전지를 도시한 단면도이다. FIG. 2 is a cross-sectional view illustrating a rechargeable battery taken along the line II ′ of FIG. 1.
도 3은 본 발명의 일 실시예에 따른 이차 전지에서 안전 벤트를 도시한 확대 단면도이다. 3 is an enlarged cross-sectional view illustrating a safety vent in a rechargeable battery according to an exemplary embodiment of the present invention.
도 4 본 발명의 일 실시예에 따른 안전 벤트의 사시도이다. 4 is a perspective view of a safety vent according to an embodiment of the present invention.
도 5는 본 발명의 일 실시예에 따른 안전 벤트의 단면도이다. 5 is a cross-sectional view of a safety vent according to an embodiment of the present invention.
도 6은 본 발명의 일 실시예에 따른 연결탭의 평면도이다. 6 is a plan view of a connection tab according to an embodiment of the present invention.
도 7 및 도 8은 본 발명의 일 실시예에 따른 이차 전지에서 안전 벤트의 작동 상태를 도시한 단면도이다.7 and 8 are cross-sectional views illustrating an operating state of a safety vent in a rechargeable battery according to an exemplary embodiment of the present invention.
이하, 첨부된 도면을 참조하여 본 발명의 바람직한 실시예를 상세히 설명하기로 한다.Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.
본 발명의 실시예들은 당해 기술 분야에서 통상의 지식을 가진 자에게 본 발명을 더욱 완전하게 설명하기 위하여 제공되는 것이며, 하기 실시예는 여러 가지 다른 형태로 변형될 수 있으며, 본 발명의 범위가 하기 실시예에 한정되는 것은 아니다. 오히려, 이들 실시예는 본 개시를 더욱 충실하고 완전하게 하고, 당업자에게 본 발명의 사상을 완전하게 전달하기 위하여 제공되는 것이다.The embodiments of the present invention are provided to more fully explain the present invention to those skilled in the art, and the following examples can be modified in various other forms, and the scope of the present invention is It is not limited to an Example. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the inventive concept to those skilled in the art.
또한, 이하의 도면에서 각 층의 두께나 크기는 설명의 편의 및 명확성을 위하여 과장된 것이며, 도면상에서 동일 부호는 동일한 요소를 지칭한다. 본 명세서에서 사용된 바와 같이, 용어 "및/또는" 는 해당 열거된 항목 중 어느 하나 및 하나 이상의 모든 조합을 포함한다. In addition, in the following drawings, the thickness or size of each layer is exaggerated for convenience and clarity of description, the same reference numerals in the drawings refer to the same elements. As used herein, the term “and / or” includes any and all combinations of one or more of the listed items.
또한, "하부(beneath)", "아래(below)", "낮은(lower)", "상부(above)", "위(upper)"와 같은 공간에 관련된 용어가 도면에 도시된 한 요소 또는 특징과 다른 요소 또는 특징의 용이한 이해를 위해 이용된다. 이러한 공간에 관련된 용어는 이차 전지의 다양한 제조 공정 또는 사용 상태에 따라 본 발명의 용이한 이해를 위한 것이며, 본 발명을 한정하기 위한 것은 아니다. 예를 들어, 도면의 이차 전지가 뒤집어지면, "하부" 또는 "아래"로 설명된 요소는 "상부" 또는 "위에"로 된다. 따라서, "아래"는 "상부" 또는 "아래"를 포괄한다.Further, terms relating to spaces such as "beneath", "below", "lower", "above", and "upper" may be referred to as an element or Used for easy understanding of the feature and other elements or features. Terms related to this space are for easy understanding of the present invention according to various manufacturing processes or use conditions of the secondary battery, and are not intended to limit the present invention. For example, when the secondary battery of the figure is turned upside down, the element described as "lower" or "below" becomes "top" or "above." Thus, "bottom" encompasses "top" or "bottom".
도 1은 본 발명의 일 실시예에 따른 이차 전지를 도시한 사시도이다. 도 2는 도 1의 I-I' 선을 따라 절취한 이차 전지를 도시한 단면도이다. 도 3은 본 발명의 일 실시예에 따른 이차 전지에서 안전 벤트를 도시한 확대 단면도이다. 도 4 본 발명의 일 실시예에 따른 안전 벤트의 사시도이다. 도 5는 본 발명의 일 실시예에 따른 안전 벤트의 단면도이다. 도 6은 본 발명의 일 실시예에 따른 연결탭의 평면도이다. 1 is a perspective view illustrating a rechargeable battery according to an exemplary embodiment of the present invention. FIG. 2 is a cross-sectional view illustrating a rechargeable battery taken along the line II ′ of FIG. 1. 3 is an enlarged cross-sectional view illustrating a safety vent in a rechargeable battery according to an exemplary embodiment of the present invention. 4 is a perspective view of a safety vent according to an embodiment of the present invention. 5 is a cross-sectional view of a safety vent according to an embodiment of the present invention. 6 is a plan view of a connection tab according to an embodiment of the present invention.
도 1 내지 도 6을 참조하면, 본 발명의 일 실시예에 따른 이차 전지(100)는 전극 조립체(110), 제 1 집전판(120), 제 2 집전판(130), 제 1 전극 단자(140), 제 2 전극 단자(150), 케이스(160), 캡 조립체(170), 안전 벤트(180) 및 연결탭(190)를 포함한다.1 to 6, a secondary battery 100 according to an embodiment of the present invention may include an electrode assembly 110, a first current collecting plate 120, a second current collecting plate 130, and a first electrode terminal ( 140, a second electrode terminal 150, a case 160, a cap assembly 170, a safety vent 180, and a connection tab 190.
상기 전극 조립체(110)는 제 1 전극(111), 제 2 전극(112) 및 제 1 전극(111)과 제 2 전극(112) 사이에 개재된 세퍼레이터(113)를 포함한다. 상기 전극 조립체(110)는 상기 제 1 전극(111)과 세퍼레이터(113) 및 제 2 전극(112)의 적층제를 젤리-롤 형태로 권취하여 형성할 수 있다. 여기서, 제 1 전극(111)은 양극으로서 작용할 수 있으며, 제 2 전극(112)은 음극으로서 작용할 수 있다.The electrode assembly 110 includes a first electrode 111, a second electrode 112, and a separator 113 interposed between the first electrode 111 and the second electrode 112. The electrode assembly 110 may be formed by winding a laminate of the first electrode 111, the separator 113, and the second electrode 112 in a jelly-roll form. Here, the first electrode 111 may act as an anode, and the second electrode 112 may act as a cathode.
상기 제 1 전극(111)은 알루미늄과 같은 금속 포일로 형성된 제 1 전극 집전체에 전이금속산화물 등의 제 1 전극 활물질을 도포함으로써 형성되며, 제 1 활물질이 도포되지 않은 영역인 제 1 전극 무지부(111a)를 포함한다. 상기 제 1 전극 무지부(111a)는 제 1 전극(111)과, 제 1 전극 외부 간의 전류 흐름의 통로가 된다.The first electrode 111 is formed by applying a first electrode active material such as transition metal oxide to a first electrode current collector formed of a metal foil such as aluminum, and the first electrode uncoated portion is an area where the first active material is not coated. (111a). The first electrode uncoated portion 111a serves as a passage for current flow between the first electrode 111 and the outside of the first electrode.
상기 제 2 전극(112)은 구리 또는 니켈과 같은 금속 포일로 형성된 제 2 전극 집전체에 흑연 또는 탄소 등의 제 2 전극 활물질을 도포함으로써 형성되며, 제 2 활물질이 도포되지 않는 영역인 제 2 전극 무지부(112a)를 포함한다. 상기 제 2 전극 무지부(112a)는 제 2 전극(112)과, 제 2 전극 외부 간의 전류 흐름의 통로가 된다.The second electrode 112 is formed by applying a second electrode active material such as graphite or carbon to a second electrode current collector formed of a metal foil such as copper or nickel, and is a region in which the second active material is not coated. And the non-coated portion 112a. The second electrode uncoated portion 112a serves as a passage for current flow between the second electrode 112 and the outside of the second electrode.
상기 세퍼레이터(113)는 제 1 전극(111)과 제 2 전극(112) 사이에 위치되어 쇼트를 방지하고 리튬 이온의 이동을 가능하게 하는 역할을 한다. 상기 세퍼레이터(113)는 폴리에틸렌이나, 폴리 프로필렌이나, 폴리 에틸렌과 폴리 프로필렌의 복합 필름으로 이루어질 수 있다.The separator 113 is positioned between the first electrode 111 and the second electrode 112 to prevent a short and to allow movement of lithium ions. The separator 113 may be made of polyethylene, polypropylene, or a composite film of polyethylene and polypropylene.
상기 제 1 집전판(120)은 알루미늄 등의 도전성 재질로 형성되며, 상기 전극 조립체(110)의 일측 단부로 돌출된 제 1 전극 무지부(111a)와 접촉됨으로써, 제 1 전극(111)과 전기적으로 연결된다. 상기 제 1 집전판(120)은 제 1 연결부(121) 및 제 1 연장부(122)를 포함한다. 상기 제 1 연결부(121)는 상기 전극 조립체(110)의 일측에 형성되며, 제 1 전극 무지부(111a)와 실질적으로 접촉하는 플레이트 형태로 형성된다. 여기서, 상기 제 1 연결부(121)는 상기 제 1 전극 무지부(111a)에 용접될 수 있다. 상기 제 1 연장부(122)는 상기 제 1 연결부(121)의 상단에서 절곡되어 후술되는 캡 플레이트(171)의 하부를 따라 연장되어 형성된다. 상기 제 1 연장부(122)는 상기 제 1 연결부(121)와 수직한 방향으로 형성되며, 상기 캡 플레이트(171)와 평행하게 형성된다. 또한, 상기 제 1 연장부(122)의 일단에는 돌출부(123)가 형성되고, 상기 돌출부(123)는 상기 캡 플레이트(171)의 하부에 접촉되어 전기적으로 연결된다. 여기서, 상기 돌출부(123)는 캡 플레이트(171)에 초음파 용접, 전기 용접, 아크 용접 등으로 용접될 수 있다. 이에 따라, 상기 캡 플레이트(171)는 제 1 전극(111)과 전기적으로 연결된다. The first collector plate 120 is formed of a conductive material such as aluminum, and is in contact with the first electrode uncoated portion 111a protruding to one end of the electrode assembly 110, thereby electrically contacting the first electrode 111. Is connected. The first current collecting plate 120 includes a first connection part 121 and a first extension part 122. The first connection portion 121 is formed on one side of the electrode assembly 110, and is formed in a plate shape substantially in contact with the first electrode uncoated portion 111a. Here, the first connection portion 121 may be welded to the first electrode uncoated portion 111a. The first extension part 122 is bent at an upper end of the first connection part 121 to extend along a lower portion of the cap plate 171 to be described later. The first extension part 122 is formed in a direction perpendicular to the first connection part 121 and is formed in parallel with the cap plate 171. In addition, a protrusion 123 is formed at one end of the first extension part 122, and the protrusion 123 is electrically connected to a lower portion of the cap plate 171. Here, the protrusion 123 may be welded to the cap plate 171 by ultrasonic welding, electric welding, arc welding, or the like. Accordingly, the cap plate 171 is electrically connected to the first electrode 111.
상기 제 2 집전판(130)은 니켈 등의 도전성 재질로 형성되며, 전극 조립체(110)의 타측 단부로 돌출된 제 2 전극 무지부(112a)와 접촉됨으로써, 제 2 전극(112)과 전기적으로 연결된다. 상기 제 2 집전판(130)은 제 2 연결부(131) 및 제 2 연장부(132)를 포함한다. 상기 제 2 연결부(131)는 상기 전극 조립체(110)의 타측에 형성되며, 제 2 전극 무지부(112a)와 실질적으로 접촉하는 플레이트 형태로 형성된다. 여기서, 상기 제 2 연결부(131)는 상기 제 2 전극 무지부(112a)에 용접될 수 있다. 상기 제 2 연장부(132)는 상기 제 2 연결부(131)의 상단에서 절곡되어 캡 플레이트(171)의 하부를 따라 연장되어 형성된다. 상기 제 2 연장부(132)는 상기 제 2 연결부(131)와 수직한 방향으로 형성되며, 상기 캡 플레이트(171)와 평행하게 형성된다. 또한, 상기 제 2 연장부(132)에는 단자홀(133)이 형성되며, 상기 단자홀(133)에는 상기 제 2 전극 단자(150)가 끼워져 결합된다. The second collector plate 130 is made of a conductive material such as nickel, and is in contact with the second electrode uncoated portion 112a protruding to the other end of the electrode assembly 110, thereby electrically contacting the second electrode 112. Connected. The second collector plate 130 includes a second connection part 131 and a second extension part 132. The second connection portion 131 is formed on the other side of the electrode assembly 110, and is formed in a plate shape substantially in contact with the second electrode uncoated portion 112a. Here, the second connection portion 131 may be welded to the second electrode uncoated portion 112a. The second extension part 132 is bent at an upper end of the second connection part 131 to extend along a lower portion of the cap plate 171. The second extension part 132 is formed in a direction perpendicular to the second connection part 131 and is formed parallel to the cap plate 171. In addition, a terminal hole 133 is formed in the second extension part 132, and the second electrode terminal 150 is fitted into the terminal hole 133.
상기 제 1 전극 단자(140)는 알루미늄 등의 도전성 재질로 형성되며, 상기 제 1 집전판(120)과 결합됨으로써, 상기 제 1 전극(111)과 전기적으로 연결된다. 상기 제 1 전극 단자(140)는 제 1 단자 몸체(141) 및 제 1 단자 연장부(142)를 포함한다. 상기 제 1 단자 몸체(141)는 상기 캡 플레이트(171)를 관통하며, 상부가 리벳팅되어 상기 캡 플레이트(171)에 고정된다. 상기 제 1 단자 연장부(142)는 상기 제 1 단자 몸체(141)의 하부에서 수평 방향으로 연장되어, 상기 캡 플레이트(171)의 하면에 밀착된다. 상기 제 1 단자 연장부(142)는 상기 제 1 단자 몸체(141)가 캡 플레이트(171)로부터 빠지지 않도록 한다. The first electrode terminal 140 is formed of a conductive material such as aluminum, and is coupled to the first current collector 120 to be electrically connected to the first electrode 111. The first electrode terminal 140 includes a first terminal body 141 and a first terminal extension 142. The first terminal body 141 passes through the cap plate 171, and an upper portion thereof is riveted to be fixed to the cap plate 171. The first terminal extension part 142 extends in the horizontal direction from the bottom of the first terminal body 141 to be in close contact with the bottom surface of the cap plate 171. The first terminal extension 142 prevents the first terminal body 141 from coming off the cap plate 171.
상기 제 2 전극 단자(150)는 니켈 등의 도전성 재질로 형성되며, 상기 제 2 집전판(130)과 결합됨으로써, 상기 제 2 전극(112)과 전기적으로 연결된다. 상기 제 2 전극 단자(150)는 제 2 단자 몸체(151) 및 제 2 단자 연장부(152)를 포함한다. 상기 제 2 단자 몸체(151)는 상기 캡 플레이트(171)를 관통하며, 상부가 리벳팅되어 상기 캡 플레이트(171)에 고정된다. 상기 제 2 단자 연장부(152)는 상기 제 2 단자 몸체(151)의 하부에서 수평 방향으로 연장되어, 상기 캡 플레이트(171)의 하면에 밀착된다. 상기 제 2 단자 연장부(152)는 상기 제 2 단자 몸체(151)가 캡 플레이트(151)로부터 빠지지 않도록 한다. 한편, 상기 제 2 단자 몸체(151) 중 상기 단자 연장부(152)의 하부와 연결된 부분은 상기 제 2 집전판(130)의 단자홀(133)에 삽입되어 전기적으로 결합된다.The second electrode terminal 150 is formed of a conductive material such as nickel, and is electrically connected to the second electrode 112 by being combined with the second current collecting plate 130. The second electrode terminal 150 includes a second terminal body 151 and a second terminal extension 152. The second terminal body 151 penetrates through the cap plate 171, and an upper portion thereof is riveted to be fixed to the cap plate 171. The second terminal extension part 152 extends in the horizontal direction from the bottom of the second terminal body 151 to be in close contact with the bottom surface of the cap plate 171. The second terminal extension 152 prevents the second terminal body 151 from coming off the cap plate 151. Meanwhile, a portion of the second terminal body 151 connected to the lower portion of the terminal extension part 152 is inserted into the terminal hole 133 of the second current collecting plate 130 and electrically coupled thereto.
상기 케이스(160)는 알루미늄, 알루미늄 합금 또는 니켈이 도금된 스틸과 같은 도전성 금속으로 형성되며, 전극 조립체(110), 제 1 집전판(120), 제 2 집전판(130), 제 1 전극 단자(140) 및 제 2 전극 단자(150)가 삽입 안착될 수 있는 개구부가 형성된 대략 육면체 형상으로 이루어진다. 여기서, 상기 케이스(160)는 하나의 극성, 예를 들어 양극으로서 작용할 수 있다. The case 160 is formed of a conductive metal such as aluminum, an aluminum alloy, or nickel plated steel, and includes an electrode assembly 110, a first current collector 120, a second current collector 130, and a first electrode terminal. The 140 and the second electrode terminal 150 may have a substantially hexahedral shape in which an opening to which the second electrode terminal 150 is inserted and formed is formed. Here, the case 160 may act as one polarity, for example, an anode.
상기 캡 조립체(170)는 상기 케이스(160)의 상부에 결합된다. 상기 캡 조립체(170)는 구체적으로, 캡 플레이트(171), 마개(172), 가스켓(173), 제 1 단자 플레이트(174), 제 2 단자 플레이트(175), 상부 절연부재(176) 및 하부 절연부재(177)를 포함한다.The cap assembly 170 is coupled to the top of the case 160. Specifically, the cap assembly 170 may include a cap plate 171, a stopper 172, a gasket 173, a first terminal plate 174, a second terminal plate 175, an upper insulating member 176, and a lower portion. Insulation member 177 is included.
상기 캡 플레이트(171)는 케이스(160)의 개구를 밀봉하며, 케이스(160)와 동일한 재질로 형성될 수 있다. 예를 들면, 상기 캡 플레이트(171)는 레이저 용접 방식으로 상기 케이스(160)에 결합될 수 있다. 여기서, 상기 캡 플레이트(171)는 케이스(160)와 동일한 극성을 가질 수 있다. 또한, 상기 캡 플레이트(171)에는 전해액을 주입하기 위한 전해액 주입구(171a)와, 안전 벤트(180)가 형성되는 벤트홀(171b)이 형성된다. 상기 벤트홀(171b)은 상기 캡 플레이트(171)의 두께에 비해 상대적으로 얇은 안전 벤트(180)를 결합시키기 위해 단차면(171c)을 가질 수 있다. The cap plate 171 seals the opening of the case 160 and may be formed of the same material as the case 160. For example, the cap plate 171 may be coupled to the case 160 by laser welding. Here, the cap plate 171 may have the same polarity as the case 160. In addition, the cap plate 171 is formed with an electrolyte injection hole 171a for injecting an electrolyte and a vent hole 171b in which a safety vent 180 is formed. The vent hole 171b may have a stepped surface 171c to couple the safety vent 180 relatively thinner than the thickness of the cap plate 171.
또한, 상기 전해액 주입구(171a)를 통해 전해액이 케이스(160) 내부로 주입된 후에는 마개(172)로 상기 전해액 주입구(171a)를 밀봉한다.In addition, after the electrolyte is injected into the case 160 through the electrolyte injection hole 171a, the electrolyte injection hole 171a is sealed with a stopper 172.
상기 가스켓(173)은 절연성 재질로 제 1 전극 단자(140) 및 제 2 전극 단자(150) 각각과 캡 플레이트(171) 사이에 형성되어 제 1 전극 단자(140) 및 제 2 전극 단자(150) 각각과 캡 플레이트(171) 사이를 밀봉시킨다. 또한, 상기 가스켓(173)은 상기 캡 플레이트(171)의 하부에서 제 1 전극 단자(140) 및 제 2 전극 단자(150) 각각과 캡 플레이트(171) 사이에 결합된다. 이러한 가스켓(173)은 외부의 수분이 이차 전지(100)의 내부에 침투하지 못하도록 하거나, 이차 전지(100)의 내부에 수용된 전해액이 외부로 유출되지 못하도록 한다.The gasket 173 is formed of an insulating material between each of the first electrode terminal 140 and the second electrode terminal 150 and the cap plate 171 to form the first electrode terminal 140 and the second electrode terminal 150. Seal between each and the cap plate 171. In addition, the gasket 173 is coupled between each of the first electrode terminal 140 and the second electrode terminal 150 and the cap plate 171 at the bottom of the cap plate 171. The gasket 173 prevents external moisture from penetrating the inside of the secondary battery 100 or prevents the electrolyte solution contained in the secondary battery 100 from flowing out.
상기 제 1 단자 플레이트(174)와 제 2 단자 플레이트(175)는 상기 제 1 전극 단자(140) 및 제 2 전극 단자(150) 각각에 결합된다. 또한, 상기 제 1,2 단자 플레이트(174, 175)가 상기 제 1,2 전극 단자(140, 150)에 각각 결합된 후, 상기 제 1,2 전극 단자(140, 150)의 상부가 각각 리벳팅됨으로써, 상기 제 1,2 전극 단자(140, 150)가 상기 제 1,2 단자 플레이트(174, 175)에 고정된다. 또한, 상기 제 1 단자 플레이트(174)에는 후술되는 연결탭(190)이 결합된다. 따라서, 상기 제 1 단자 플레이트(174)에는 연결탭(190)이 결합되는 단차부(174a)가 형성된다.The first terminal plate 174 and the second terminal plate 175 are coupled to each of the first electrode terminal 140 and the second electrode terminal 150. In addition, after the first and second terminal plates 174 and 175 are coupled to the first and second electrode terminals 140 and 150, respectively, the upper portions of the first and second electrode terminals 140 and 150 are riveted, respectively. The first and second electrode terminals 140 and 150 are fixed to the first and second terminal plates 174 and 175. In addition, the connection tab 190 to be described later is coupled to the first terminal plate 174. Therefore, the first terminal plate 174 is formed with a stepped portion 174a to which the connection tab 190 is coupled.
상기 상부 절연부재(176)는 제 1,2단자 플레이트(174, 175)와 캡 플레이트(171) 사이에 위치하며, 상기 제 1 전극 단자(140) 및 제 2 전극 단자(150)가 각각 끼워지도록 형성된다. 상기 상부 절연부재(176)는 상기 제 1,2단자 플레이트(174, 175)를 통해서 캡 플레이트(171)와 가스켓(173)에 밀착된다. 이러한 상부 절연부재(176)는 제 1 전극 단자(140) 및 제 2 전극 단자(150)와 캡 플레이트(171)를 절연시킨다.The upper insulating member 176 is positioned between the first and second terminal plates 174 and 175 and the cap plate 171 so that the first electrode terminal 140 and the second electrode terminal 150 are fitted therein, respectively. Is formed. The upper insulating member 176 is in close contact with the cap plate 171 and the gasket 173 through the first and second terminal plates 174 and 175. The upper insulating member 176 insulates the first electrode terminal 140 and the second electrode terminal 150 from the cap plate 171.
상기 하부 절연부재(177)는 제 1 집전판(120) 및 제 2 집전판(130) 각각과 캡 플레이트(171) 사이에 형성되어, 제 1 집전판(120) 및 제 2 집전판(130) 각각과 캡 플레이트(171) 사이의 불필요한 단락의 발생을 방지한다. 구체적으로, 상기 하부 절연부재(177)는 제 1 집전판(120)의 제 1 연장부(122)와 캡 플레이트(171) 사이에 형성된다. 더불어, 상기 하부 절연부재(177)는 상기 제 1 전극 단자(140)의 제 1 단자 연장부(142)와 상기 제 1 집전판(120)의 제 1 연장부(122) 사이에 위치한다. 따라서, 상기 제 1 전극 단자(140)는 상기 하부 절연부재(177)에 의해 상기 제 1 집전판(120)과 직접적으로 접촉하지 않는다. 또한, 상기 하부 절연부재(177)는 제 2 집전판(130)의 제 2 연장부(132)와 캡 플레이트(171) 사이에 형성된다.The lower insulating member 177 is formed between each of the first current collector plate 120 and the second current collector plate 130 and the cap plate 171, and thus the first current collector plate 120 and the second current collector plate 130. The occurrence of unnecessary short circuit between each and the cap plate 171 is prevented. In detail, the lower insulating member 177 is formed between the first extension part 122 of the first current collecting plate 120 and the cap plate 171. In addition, the lower insulating member 177 is positioned between the first terminal extension part 142 of the first electrode terminal 140 and the first extension part 122 of the first current collecting plate 120. Therefore, the first electrode terminal 140 does not directly contact the first current collecting plate 120 by the lower insulating member 177. In addition, the lower insulating member 177 is formed between the second extension part 132 of the second current collecting plate 130 and the cap plate 171.
상기 안전 벤트(180)는 상기 캡 플레이트(171)의 벤트홀(171b)에 결합된다. 구체적으로, 상기 안전 벤트(180)는 상기 벤트홀(171b)의 단차면(171c)에 걸쳐져 결합되어, 상기 벤트홀(171b)을 밀봉한다. 상기 안전 벤트(180)는 상기 캡 플레이트(171)와 동일한 재질로 형성되며, 상기 캡 플레이트(171)와 전기적으로 연결된다. 또한, 상기 안전 벤트(180)는 과충전 또는 과방전 등으로 상기 이차 전지(100)의 내부압력이 설정된 파단압력에 이르면 파단되어 상기 벤트홀(171b)이 개방되고, 이에 따라 이차 전지(100)의 폭발을 방지할 수 있다. The safety vent 180 is coupled to the vent hole 171b of the cap plate 171. Specifically, the safety vent 180 is coupled across the stepped surface 171c of the vent hole 171b to seal the vent hole 171b. The safety vent 180 is formed of the same material as the cap plate 171 and is electrically connected to the cap plate 171. In addition, the safety vent 180 breaks when the internal pressure of the secondary battery 100 reaches a set breaking pressure due to overcharging or overdischarging, so that the vent hole 171b is opened, and thus the secondary battery 100 is opened. Prevent explosion.
상기 안전 벤트(180)는 고정부(181), 파단부(182), 반전부(183) 및 결합부(184)를 포함할 수 있다. The safety vent 180 may include a fixing part 181, a breaking part 182, an inverting part 183, and a coupling part 184.
상기 고정부(181)는 상기 안전 벤트(180)의 가장자리 부분으로, 상기 벤트홀(171b)의 단차면(171c)에 결합된다. 여기서, 상기 고정부(181)는 상기 단차면(171c)에 용접에 의해 고정될 수 있다. The fixing part 181 is an edge portion of the safety vent 180 and is coupled to the stepped surface 171c of the vent hole 171b. Here, the fixing part 181 may be fixed to the step surface 171c by welding.
상기 파단부(182)는 상기 고정부(181)의 내측에 위치하며, 이차 전지(100)의 내부압력이 설정된 파단압력 보다 높으면 파단되는 부분이다. 따라서, 상기 파단부(182)의 하면에는 노치(182a)가 형성되어, 안전 벤트(180)의 파단을 용이하게 할 수 있다. 상기 안전 벤트(180)의 파단압력은 상기 파단부(182)의 두께와 형태 및 반전부(183)의 오목한 정도로 설정할 수 있다. The breaking part 182 is positioned inside the fixing part 181 and is broken when the internal pressure of the secondary battery 100 is higher than the set breaking pressure. Therefore, the notch 182a is formed on the lower surface of the breaker 182, so that the safety vent 180 may be easily broken. The breaking pressure of the safety vent 180 may be set to the thickness and shape of the breaking part 182 and the concave degree of the inverting part 183.
상기 반전부(183)는 상기 파단부(182)의 내측, 즉, 상기 안전 벤트(180)의 중심에 위치하며, 케이스(160)의 내부를 향해 볼록하도록 형성된다. 다시 말해, 상기 반전부(183)는 캡 플레이트(171)의 표면에 비해 오목하게 형성된 반전 플레이트로 이루어진다. 따라서, 상기 이차 전지(100)의 내부압력이 설정된 기준압력보다 높아지면, 상기 반전부(183)가 반전되어 위로 볼록하게 형성된다. 더불어, 상기 이차 전지(100)의 내부압력이 파단압력보다 높아지면, 상기 파단부(182)가 파단된다. The inverting portion 183 is positioned inside the breaker 182, that is, at the center of the safety vent 180, and is formed to be convex toward the inside of the case 160. In other words, the inverting portion 183 is formed of a reversing plate formed concave than the surface of the cap plate 171. Therefore, when the internal pressure of the secondary battery 100 is higher than the set reference pressure, the inverting portion 183 is inverted to be convex upward. In addition, when the internal pressure of the secondary battery 100 is higher than the breaking pressure, the breaking part 182 is broken.
상기 반전부(183)의 상부에는 상기 안전 벤트(180)의 두께에 비해 상대적으로 두께가 두꺼운 결합부(184)가 형성된다. 상기 결합부(184)에는 연결탭(190)이 결합되어, 상기 제 1 전극 단자(120)를 제 1 전극(111)과 전기적으로 연결시킨다. 상기 결합부(184)는 상기 연결탭(190)과 용접이 되는 부분이므로, 결합부(184)와 연결탭(190)의 용접시 안전 벤트(180)가 손상되지 않을 정도의 두께를 가져야 한다. 또한, 상기 결합부(184)의 상부에는 결합 돌기(184a)가 형성된다. 상기 결합 돌기(184a)에는 상기 연결탭(190)이 끼워지고, 상기 결합 돌기(184a)와 연결탭(190)의 접합면이 용접된다. 여기서, 상기 결합 돌기(184a)가 돌출된 두께는 상기 연결탭(190)의 두께와 동일하게 형성된다. 따라서, 상기 결합 돌기(184a)에 결합된 연결탭(190)은 결합 돌기(184a)의 상면과 동일 평면을 이루게 된다. A coupling portion 184 having a relatively thick thickness is formed on the upper portion of the inverting portion 183 compared to the thickness of the safety vent 180. A connection tab 190 is coupled to the coupling portion 184 to electrically connect the first electrode terminal 120 to the first electrode 111. Since the coupling part 184 is welded with the connection tab 190, the coupling part 184 has a thickness such that the safety vent 180 is not damaged when the coupling part 184 and the connection tab 190 are welded. In addition, a coupling protrusion 184a is formed at an upper portion of the coupling portion 184. The connection tab 190 is fitted to the coupling protrusion 184a, and a joint surface of the coupling protrusion 184a and the connection tab 190 is welded. In this case, the thickness of the coupling protrusion 184a protrudes from the thickness of the connection tab 190. Therefore, the connection tab 190 coupled to the coupling protrusion 184a forms the same plane as the upper surface of the coupling protrusion 184a.
상기 연결탭(190)은 상기 제 1 단자 플레이트(174)와 상기 안전 벤트(180) 사이에 연결되어, 제 1 단자 플레이트(174)와 안전 벤트(180)를 전기적으로 연결한다. 이에 따라, 상기 연결탭(190)은 제 1 전극 단자(120)를 제 1 전극(111)에 전기적으로 연결시킨다. 구체적으로, 제 1 전극 단자(120)는 제 1 단자 플레이트(174), 연결탭(190), 안전 벤트(180), 캡 플레이트(171) 및 제 1 집전판(120)을 통해서 제 1 전극(111)에 전기적으로 연결된다. 상기 연결탭(190)은 상기 제 1 단자 플레이트(174)에 전기적으로 연결되는 단자 접속부(191), 상기 안전 벤트(180)에 전기적으로 연결되는 벤트 접속부(192) 및 상기 단자 접속부(191)와 벤트 접속부(192)를 전기적으로 연결하는 연결부(193)를 포함한다. 이러한 연결탭(190)은 알루미늄, 알루미늄 합금과 같은 금속으로 형성될 수 있다.The connection tab 190 is connected between the first terminal plate 174 and the safety vent 180 to electrically connect the first terminal plate 174 and the safety vent 180. Accordingly, the connection tab 190 electrically connects the first electrode terminal 120 to the first electrode 111. Specifically, the first electrode terminal 120 is connected to the first electrode through the first terminal plate 174, the connection tab 190, the safety vent 180, the cap plate 171, and the first current collecting plate 120. 111) is electrically connected. The connection tab 190 may include a terminal connection part 191 electrically connected to the first terminal plate 174, a vent connection part 192 electrically connected to the safety vent 180, and the terminal connection part 191. And a connecting portion 193 for electrically connecting the vent connecting portion 192. The connection tab 190 may be formed of a metal such as aluminum or an aluminum alloy.
상기 단자 접속부(191)는 대략 사각형의 플레이트 형상으로, 일단이 상기 제 1 단자 플레이트(174)의 단차부(174a)에 결합되어 전기적으로 연결된다. 이때, 상기 단자 접속부(191)는 상기 단자부(174a)에 초음파 용접, 저항 용접, 스팟 용접 등으로 용접될 수 있다. The terminal connecting portion 191 has a substantially rectangular plate shape, one end of which is electrically connected to the stepped portion 174a of the first terminal plate 174. In this case, the terminal connecting portion 191 may be welded to the terminal portion 174a by ultrasonic welding, resistance welding, spot welding, or the like.
상기 벤트 접속부(192)는 상기 안전 벤트(180)의 결합부(184)에 결합되어 전기적으로 연결된다. 상기 벤트 접속부(192)에는 결합홀(192a)이 형성되며, 상기 결합홀(192a)에는 상기 결합부(184)의 결합 돌기(184a)가 결합된다. 또한, 상기한 바와 같이, 상기 연결탭(190)의 두께는 결합 돌기(184a)의 두께와 동일하므로, 상기 벤트 접속부(192)와 결합 돌기(184a)의 상면은 동일 평면을 이룬다. 이때, 상기 결합 돌기(184a)와 결합홀(192a)의 접합면을 용접하면, 접합면 주위의 결합 돌기(184a) 및 결합홀(192a)의 일부가 녹아 용융된다. 따라서, 안전 벤트(180)와 연결탭(190) 사이의 기계적 결합 강도가 향상되며, 이러한 용접 방식을 맞대기 용접이라고 한다. 이러한 맞대기 용접은 결합부(184)와 연결탭(190)의 용접 품질을 향상시킨다. 종래에는 연결탭을 결합부의 상부에 올려놓고 연결탭의 상부와 결합부의 하부를 용접하는 겹치기 용접을 하였으나, 이러한 겹치기 용접은 불량률이 상대적으로 높은 편이다. 따라서, 본 발명에서는 연결탭(190)에 결합홀(192a)을 형성하고 안전 벤트(180)에 결합 돌기(184a)를 형성하며, 상기 결합홀(192a)에 결합 돌기(184a)를 결합한 뒤 그 접합면을 용접함으로써, 용접 품질을 향상시킬 수 있게 된다. The vent connection 192 is coupled to and electrically connected to the coupling part 184 of the safety vent 180. A coupling hole 192a is formed in the vent connection part 192, and a coupling protrusion 184a of the coupling part 184 is coupled to the coupling hole 192a. In addition, as described above, since the thickness of the connection tab 190 is the same as the thickness of the coupling protrusion 184a, the upper surface of the vent connecting portion 192 and the coupling protrusion 184a forms the same plane. At this time, when the joining surface of the joining protrusion 184a and the joining hole 192a is welded, a part of the joining protrusion 184a and the joining hole 192a around the joining surface are melted and melted. Therefore, the mechanical coupling strength between the safety vent 180 and the connection tab 190 is improved, and this welding method is called butt welding. Such butt welding improves the welding quality of the coupling part 184 and the connection tab 190. Conventionally, the overlapping welding for placing the connection tab on the upper part of the coupling part and welding the upper part of the connection tab and the lower part of the coupling part is performed, but the overlapping welding tends to have a relatively high defect rate. Therefore, in the present invention, the coupling hole 192a is formed in the connection tab 190 and the coupling protrusion 184a is formed in the safety vent 180, and the coupling protrusion 184a is coupled to the coupling hole 192a. By welding the joint surface, the welding quality can be improved.
상기 연결부(193)는 상기 단자 접속부(191)와 벤트 접속부(192)를 연결하며, 경사지게 형성된다. 왜냐하면, 상기 단자 접속부(191)가 결합되는 제 1 단자 플레이트(174)는 캡 플레이트(171)로부터 돌출되게 형성되어 상대적으로 높이가 높게 형성되고, 상기 벤트 접속부(192)가 결합되는 안전 벤트(180)는 캡 플레이트(171)로부터 오목하게 형성되어 상대적으로 높이가 낮기 때문이다. 또한, 상기 연결부(193)에는 노치(193a)가 형성되어, 상기 안전 벤트(180)가 파단될 때, 상기 연결탭(190)도 함께 파단될 수 있다. The connection part 193 connects the terminal connection part 191 and the vent connection part 192 and is formed to be inclined. Because the first terminal plate 174 to which the terminal connecting portion 191 is coupled is formed to protrude from the cap plate 171 to have a relatively high height, and the safety vent 180 to which the vent connecting portion 192 is coupled. Is because it is formed concave from the cap plate 171 and the height is relatively low. In addition, the notch 193a is formed at the connection portion 193, and when the safety vent 180 is broken, the connection tab 190 may be broken together.
이와 같이, 본 발명의 일 실시예에 따른 이차 전지(100)는 결합 돌기(184a)를 갖는 안전 벤트(180)와 상기 결합 돌기(184a)에 결합되는 결합홀(192a)을 갖는 연결탭(190)을 구비하고, 상기 결합 돌기(184a)와 결합홀(192a) 사이의 결합면을 맞대기 용접함으로써, 용접 품질을 향상시킬 수 있게 된다. 따라서, 본 발명에 따른 이차 전지(100)는 용접 불량을 줄여, 생산 비용을 절감하며 제품의 신뢰성을 향상시킬 수 있게 된다. As described above, the secondary battery 100 according to the embodiment of the present invention has a safety vent 180 having a coupling protrusion 184a and a connection tab 190 having a coupling hole 192a coupled to the coupling protrusion 184a. ), And by butt welding the coupling surface between the coupling protrusion 184a and the coupling hole 192a, the welding quality can be improved. Therefore, the secondary battery 100 according to the present invention can reduce the welding defect, reduce the production cost and improve the reliability of the product.
도 7 및 도 8은 본 발명의 일 실시예에 따른 이차 전지에서 안전 벤트의 작동 상태를 도시한 단면도이다. 도 7 및 도 8을 참조하여, 본 발명의 일 실시예에 따른 이차 전지에서 안전 벤트의 작동 방법을 살펴보기로 한다. 7 and 8 are cross-sectional views illustrating an operating state of a safety vent in a rechargeable battery according to an exemplary embodiment of the present invention. Referring to FIGS. 7 and 8, a method of operating a safety vent in a rechargeable battery according to an exemplary embodiment will be described.
먼저, 도 7에 도시된 바와 같이, 이차 전지(100)의 내부압력이 기준압력보다 높아지면, 상기 안전 벤트(180)의 반전부(183)가 반전되어 위로 볼록하게 형성된다. 또한, 상기 반전부(183)가 반전됨에 따라, 상기 연결탭(190)의 벤트 접속부(192)가 상부로 올라가고 연결부(193)가 대략 평평하게 형성되게 된다. First, as shown in FIG. 7, when the internal pressure of the secondary battery 100 is higher than the reference pressure, the inverting portion 183 of the safety vent 180 is inverted to be convex upward. In addition, as the inversion unit 183 is inverted, the vent connection unit 192 of the connection tab 190 rises upward and the connection unit 193 is formed to be substantially flat.
그리고 나서, 도 8에 도시된 바와 같이, 이차 전지(100)의 내부압력이 파단압력보다 높아지면, 상기 안전 벤트(180)의 파단부(182)가 파단되어 벤트홀(171b)이 개방된다. 여기서, 상기 파단부(182)에는 노치(182a)가 형성되어 있으므로 파단이 용이하다. 또한, 상기 안전 벤트(180)가 파단될 때, 연결부(193)에 형성된 노치(193a)에 의해 연결탭(190)도 함께 파단될 수 있다. 이와 같이, 안전 벤트(180)가 파단되면 상기 캡 플레이트(171)와 제 1 단자 플레이트(174) 사이의 전기적 연결이 끊어지므로, 상기 제 1 전극 단자(120)와 제 1 전극(111) 간의 전기적 연결이 끊어지게 된다. 따라서, 상기 이차 전지(100)의 전류가 차단된다. Then, as shown in FIG. 8, when the internal pressure of the secondary battery 100 is higher than the breaking pressure, the breaking part 182 of the safety vent 180 is broken to open the vent hole 171b. Here, since the notch 182a is formed in the break portion 182, break is easy. In addition, when the safety vent 180 is broken, the connection tab 190 may be broken together by the notch 193a formed in the connection unit 193. As such, when the safety vent 180 is broken, the electrical connection between the cap plate 171 and the first terminal plate 174 is broken, so that the electrical connection between the first electrode terminal 120 and the first electrode 111 is lost. The connection will be lost. Therefore, the current of the secondary battery 100 is cut off.
이상에서 설명한 것은 본 발명에 의한 이차 전지를 실시하기 위한 하나의 실시예에 불과한 것으로서, 본 발명은 상기한 실시예에 한정되지 않고, 이하의 특허청구범위에서 청구하는 바와 같이 본 발명의 요지를 벗어남이 없이 당해 발명이 속하는 분야에서 통상의 지식을 가진 자라면 누구든지 다양한 변경 실시가 가능한 범위까지 본 발명의 기술적 정신이 있다고 할 것이다.What has been described above is just one embodiment for carrying out the secondary battery according to the present invention, and the present invention is not limited to the above-described embodiment, and the claims are deviated from the gist of the present invention. Without this, anyone skilled in the art to which the present invention pertains will have the technical spirit of the present invention to the extent that various modifications can be made.

Claims (10)

  1. 제 1 전극, 제 2 전극 및 상기 제 1 전극과 제 2 전극 사이에 개재된 세퍼레이터를 포함하는 전극 조립체;An electrode assembly including a first electrode, a second electrode, and a separator interposed between the first electrode and the second electrode;
    상기 전극 조립체를 수용하는 케이스;A case accommodating the electrode assembly;
    상기 케이스의 상부에 결합되고 상기 제 1 전극과 전기적으로 연결되며, 일측에 안전 벤트가 형성된 캡 플레이트;A cap plate coupled to an upper portion of the case and electrically connected to the first electrode, and having a safety vent formed at one side thereof;
    상기 캡 플레이트를 관통하여 형성된 제 1 전극 단자; 및A first electrode terminal formed through the cap plate; And
    상기 제 1 전극 단자와 상기 안전 벤트를 전기적으로 연결하는 연결탭을 포함하고,A connection tab electrically connecting the first electrode terminal and the safety vent,
    상기 안전 벤트의 중심에는 결합 돌기가 형성되고, 상기 연결탭에는 상기 결합 돌기가 결합되는 결합홀이 형성된 것을 특징으로 하는 이차 전지.A secondary battery, characterized in that a coupling protrusion is formed in the center of the safety vent, the coupling tab is formed with a coupling hole to which the coupling protrusion is coupled.
  2. 제 1 항에 있어서,The method of claim 1,
    상기 결합 돌기와 상기 결합홀의 접합면을 용접하여, 상기 연결탭과 상기 안전 벤트가 전기적으로 연결된 것을 특징으로 하는 이차 전지.And a joint surface of the coupling protrusion and the coupling hole to electrically connect the connection tab and the safety vent.
  3. 제 1 항에 있어서,The method of claim 1,
    상기 안전 벤트는The safety vent
    상기 캡 플레이트에 고정되는 고정부;A fixing part fixed to the cap plate;
    상기 고정부의 내측에 위치하고, 노치가 형성된 파단부;A break portion located inside the fixing portion and having a notch formed therein;
    상기 파단부의 내측에 위치하고, 상기 캡 플레이트로부터 오목하게 형성된 반전 플레이트로 이루어진 반전부; 및An inverting part disposed inside the breaking part and formed of a inverting plate concave from the cap plate; And
    상기 반전부의 상부에 위치하고 상기 반전부의 두께보다 두껍게 형성되며, 상기 연결탭이 결합되는 결합부;를 포함하는 것을 특징으로 하는 이차 전지.And a coupling part disposed above the inversion part and formed to be thicker than a thickness of the inversion part and to which the connection tab is coupled.
  4. 제 3 항에 있어서,The method of claim 3, wherein
    상기 결합 돌기는 상기 결합부의 상부에 형성된 것을 특징으로 하는 이차 전지.The coupling protrusion is a secondary battery, characterized in that formed on top of the coupling portion.
  5. 제 1 항에 있어서,The method of claim 1,
    상기 연결탭은 The connection tab
    상기 제 1 전극 단자에 전기적으로 연결되는 단자 접속부;A terminal connection part electrically connected to the first electrode terminal;
    상기 안전 벤트에 전기적으로 연결되는 벤트 접속부; 및A vent connection electrically connected to the safety vent; And
    상기 단자 접속부와 상기 벤트 접속부를 연결하며, 경사지게 형성된 연결부;를 포함하는 것을 특징으로 하는 이차 전지.And a connection part connecting the terminal connection part and the vent connection part and formed to be inclined.
  6. 제 5 항에 있어서,The method of claim 5, wherein
    상기 결합홀은 상기 벤트 접속부에 형성된 것을 특징으로 하는 이차 전지.The coupling hole is a secondary battery, characterized in that formed in the vent connection.
  7. 제 5 항에 있어서,The method of claim 5, wherein
    상기 단자 접속부에는 노치가 형성된 것을 특징으로 하는 이차 전지.The secondary battery, characterized in that the notch is formed in the terminal connection portion.
  8. 제 1 항에 있어서,The method of claim 1,
    상기 캡 플레이트의 상부로 돌출된 상기 제 1 전극 단자에 결합된 제 1 단자 플레이트를 더 포함하고, Further comprising a first terminal plate coupled to the first electrode terminal protruding to the top of the cap plate,
    상기 제 1 단자 플레이트에는 상기 연결탭이 결합되는 단차부가 형성된 것을 특징으로 하는 이차 전지.Secondary battery, characterized in that the stepped portion is formed in the first terminal plate is coupled to the connection tab.
  9. 제 1 항에 있어서,The method of claim 1,
    상기 제 1 전극과 전기적으로 연결된 제 1 집전판을 더 포함하고,Further comprising a first collector plate electrically connected to the first electrode,
    상기 제 1 집전판은 제 1 전극 무지부와 연결된 제 1 연결부; 및The first current collector may include a first connection part connected to a first electrode uncoated part; And
    상기 제 1 연결부의 상단에서 절곡되어 상기 캡 플레이트와 평행하게 형성된 제 1 연장부를 포함하고,A first extension portion bent at an upper end of the first connection portion and formed in parallel with the cap plate;
    상기 제 1 연장부의 일단에는 상부로 돌출되어 상기 캡 플레이트와 전기적으로 연결된 돌출부가 형성된 것을 특징으로 하는 이차 전지.One end of the first extension part is a secondary battery, characterized in that the protrusion protrudes upwardly and electrically connected to the cap plate.
  10. 제 9 항에 있어서,The method of claim 9,
    상기 제 1 전극 단자와 상기 제 1 연장부 사이에는 하부 절연부재가 형성된 것을 특징으로 하는 이차 전지.A secondary battery, wherein a lower insulating member is formed between the first electrode terminal and the first extension part.
PCT/KR2018/001064 2017-04-25 2018-01-24 Secondary battery WO2018199438A1 (en)

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KR101093691B1 (en) * 2009-07-09 2011-12-15 에스비리모티브 주식회사 Rechargeable battery
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