Rechargeable battery

Abstract

A rechargeable battery includes: an electrode assembly including a first electrode, a second electrode, and a separator between the first electrode and the second electrode; a housing configured to be connected to the first electrode and accommodate the electrode assembly, and including an opening to receive the electrode assembly; a cover plate configured to be coupled to the housing to cover a peripheral area of the opening, and including a through hole to expose a central area of the opening; and a terminal plate configured to be connected to the second electrode and insulatingly bonded to the cover plate, and including a flange portion covering the through hole and a protruding portion protruding from the flange portion to pass through the through hole.

Description

[0001] Cross - reference to related applications

[0002] This application claims the priority and benefit of Korean Patent Application No. 10 - 2020 - 0076595, filed with the Korean Intellectual Property Office on June 23, 2020, the entire disclosure of which is incorporated herein by reference. Technical Field

[0003] Aspects of embodiments of the present disclosure relate to a rechargeable battery. Background Art

[0004] Generally, a rechargeable battery is a battery that can be repeatedly charged and discharged.

[0005] In recent years, as the demand for wearable devices such as headsets, earbuds, smartwatches, and body - attached medical devices that use wireless communication such as Bluetooth has increased, the demand for ultra - small rechargeable batteries installed in wearable devices is increasing.

[0006] Since both electrode terminals of such an ultra - small rechargeable battery have small sizes, when an assembly error occurs between the two electrode terminals, a short - circuit may occur between the two electrode terminals.

[0007] The above information disclosed in this background art section is only for enhancing the understanding of the background of the present invention, and thus, it may include information that does not constitute the prior art known to a person of ordinary skill in the art in this country. Summary of the Invention

[0008] According to an aspect of one or more embodiments of the present invention, a rechargeable battery is provided in which, even when an assembly error occurs therein, a short - circuit between two electrode terminals can be suppressed.

[0009] According to another aspect of one or more embodiments of the present invention, a rechargeable battery is provided in which damage to an electrode terminal caused by pressure can be suppressed.

[0010] According to another aspect of one or more embodiments of the present invention, a rechargeable battery is provided in which, even when the internal temperature and pressure of the rechargeable battery unexpectedly increase, the risk of explosion can be suppressed.

[0011] According to one or more embodiments, a rechargeable battery includes: an electrode assembly including a first electrode, a second electrode, and a separator between the first electrode and the second electrode; a housing configured to be connected to the first electrode and accommodate the electrode assembly, and including an opening to receive the electrode assembly; a cover plate configured to be coupled to the housing to cover a peripheral area of the opening, and including a through hole to expose a central area of the opening; and a terminal plate configured to be connected to the second electrode and insulatingly bonded to the cover plate, and including a flange portion covering the through hole and a protrusion protruding from the flange portion to pass through the through hole, wherein the protrusion includes a curved surface extending from a surface of the flange portion.

[0012] The protrusion may further include an inclined surface extending from the curved surface and passing through the through hole.

[0013] A first length between the inclined surface and an edge of the through hole may be longer than a second length between the curved surface and the edge of the through hole.

[0014] The rechargeable battery may further include a heat-melt layer between the cover plate and the flange portion and configured to insulatingly bond the cover plate and the flange portion.

[0015] The heat-melt layer may melt at a predetermined temperature.

[0016] The flange portion may be disposed on the cover plate, and the protrusion may pass through the through hole to connect to the second electrode.

[0017] The flange portion may be provided between the cover plate and the electrode assembly to connect to the second electrode, and the protrusion may pass through the through hole to be exposed to the outside of the cover plate.

[0018] The flange portion may have an area larger than an area of the protrusion.

[0019] The flange portion may have a thickness thinner than a thickness of the protrusion.

[0020] The flange portion and the protrusion may be integrally formed.

[0021] The housing and the cover plate may have the same polarity as the first electrode, and the terminal plate may have the same polarity as the second electrode.

[0022] The electrode assembly may further include: a first electrode tab extending from the first electrode to be coupled to the housing; and a second electrode tab extending from the second electrode to be coupled to the terminal plate.

[0023] According to one or more embodiments, a rechargeable battery is provided in which short - circuits between two electrode terminals can be suppressed even when assembly errors occur therein.

[0024] Furthermore, according to one or more embodiments, a rechargeable battery is provided in which damage to the electrode terminals caused by pressure can be suppressed.

[0025] Further still, according to one or more embodiments, a rechargeable battery is provided in which the risk of explosion can be suppressed even when the internal temperature and pressure of the rechargeable battery increase unexpectedly. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 A perspective view of a rechargeable battery according to one embodiment is illustrated.

[0027] Figure 2 Illustrating along Figure 1 a cross - sectional view taken along line II - II in

[0028] Figure 3 Illustrating Figure 2 a cross - sectional view of region “A” in

[0029] Figure 4 A cross - sectional view of a rechargeable battery according to another embodiment is illustrated.

[0030] Figure 5 Illustrating Figure 4 a cross - sectional view of region “B” in

[0031] DESCRIPTION OF REFERENCE NUMERALS

[0032] 100: Electrode assembly 200: Housing

[0033] 300: Cover plate 400: Terminal plate

[0034] 410: Flange portion 420: Protrusion

[0035] CS: Curved surface DETAILED DESCRIPTION

[0036] The present invention will be described more fully hereinafter with reference to the accompanying drawings, in which some example embodiments of the invention are shown. As those skilled in the art will recognize, the described embodiments can be modified in various different ways without departing from the spirit or scope of the invention. The drawings and the description are to be regarded as illustrative in nature and not restrictive. Like reference numerals refer to like elements throughout the specification.

[0037] In addition, unless otherwise explicitly stated to the contrary, it should be understood that terms such as "comprising", "including", or "having" used in this specification denote the presence of the described features, numbers, steps, operations, components, parts, and / or combinations thereof, but do not preclude the presence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

[0038] In addition, in this specification, it should be understood that when a component is referred to as being "connected" or "coupled" to another component, it can be directly connected or coupled to that other component, or connected or coupled to that other component with one or more other components intervening therebetween.

[0039] Unless the context otherwise clearly indicates, the singular form will include the plural form.

[0040] It should be understood that although terms such as "first", "second", etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are used to distinguish one element from another. For example, a first element may be referred to as a "second" element, and similarly, a second element may be referred to as a "first" element, without departing from the scope of the exemplary embodiments of the inventive concept. Unless the context otherwise clearly indicates, terms in the singular form may include the plural form.

[0041] In addition, terms such as "below", "under", "above", "over", etc. are used to describe the relationship of the configurations shown in the figures. However, these terms are used as relative concepts and are described with reference to the directions indicated in the accompanying drawings.

[0042] Unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which the inventive concept pertains. It should also be understood that terms defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant art, and should not be interpreted in an ideal or overly formal sense unless explicitly so defined herein.

[0043] Herein, reference will be made to Figures 1 to 3 describe a rechargeable battery according to an embodiment.

[0044] The rechargeable battery according to an embodiment is an ultra-small rechargeable battery and may include a coin battery or a button battery, but the present invention is not limited thereto, and in another embodiment, it may include a cylindrical battery or a pin-type battery.

[0045] Here, the coin battery or button battery is a thin coin-shaped or button-shaped battery, and may refer to a battery having a height-to-diameter ratio (height / diameter) of 1 or less, but is not limited thereto. In one embodiment, the coin battery or button battery is cylindrical and has a circular horizontal cross-section, but the present invention is not limited thereto, and in another embodiment, the horizontal cross-section may be elliptical or polygonal. In this case, the diameter may refer to the maximum distance of the battery in the horizontal direction of the battery, and the height may refer to the maximum distance of the battery in the vertical direction of the battery (the distance from the flat bottom surface of the battery to the flat uppermost surface).

[0046] Figure 1 Illustrate a perspective view of a rechargeable battery according to an embodiment; and Figure 2 Illustrate along Figure 1 The cross-sectional view taken along line II-II in

[0047] See Figure 1 and Figure 2 According to an embodiment, the rechargeable battery 1000 includes an electrode assembly 100, a case 200, a cover plate 300, a terminal plate 400, and a thermal fusion layer 500.

[0048] The electrode assembly 100 is received in the case 200. The lower portion of the electrode assembly 100 faces the bottom of the case 200, and the upper portion of the electrode assembly 100 faces the cover plate 300 and the terminal plate 400 that cover the opening 210 of the case 200. In one embodiment, the upper and lower portions of the electrode assembly 100 may have a planar shape parallel to each other, but are not limited thereto.

[0049] The electrode assembly 100 includes a first electrode 110, a second electrode 120, a separator 130, a first electrode tab 140, and a second electrode tab 150.

[0050] The first electrode 110 and the second electrode 120 are spaced apart from each other, and a separator 130 containing an insulating material is disposed between the first electrode 110 and the second electrode 120. In one embodiment, the first electrode 110 may be an anode, and the second electrode 120 may be a cathode, but the present invention is not limited thereto, and in another embodiment, the first electrode 110 may be a cathode, and the second electrode 120 may be an anode.

[0051] In one embodiment, the first electrode 110 has a shape of a strip extending in one direction, and includes an anode coated region and an anode uncoated region. The anode coated region is a region where a current collector of a metal foil (e.g., copper foil) is coated with an anode active material layer, and the anode uncoated region is a region where the active material is not coated. The anode uncoated region may be disposed at an end in the extending direction of the first electrode 110.

[0052] In one embodiment, the second electrode 120 has a strip shape and is spaced apart from the first electrode 110 to extend in a direction. The separator 130 is interposed between the first electrode 110 and the second electrode 120. The second electrode 120 includes a cathode coated region and a cathode uncoated region. The cathode coated region is the region where the current collector of the metal foil (e.g., aluminum foil) is coated with the cathode active material layer, and the cathode uncoated region is the region where the active material is not coated. The cathode uncoated region may be provided at the end of the second electrode 120 in the extending direction.

[0053] The separator 130 extends between the first electrode 110 and the second electrode 120 in a direction to prevent or substantially prevent a short circuit between the first electrode 110 and the second electrode 120.

[0054] In one embodiment, the first electrode 110, the separator 130, and the second electrode 120 are sequentially stacked and wound into a jelly roll shape, but are not limited thereto, and may be formed into any of various known shapes. Each of the first electrode 110, the second electrode 120, and the separator 130 may include any of various known materials.

[0055] The first electrode tab 140 extends from the first electrode 110 of the electrode assembly 100 to the housing 200. The first electrode tab 140 is coupled to the bottom of the housing 200 to connect the first electrode 110 and the housing 200. The first electrode tab 140 contacts the first electrode 110 and the housing 200. Due to the first electrode tab 140, the housing 200 has the same polarity as the first electrode 110.

[0056] The second electrode tab 150 extends from the second electrode 120 of the electrode assembly 100 to the terminal board 400. The second electrode tab 150 is coupled to the protrusion 420 of the terminal board 400 to connect the second electrode 120 and the terminal board 400. The second electrode tab 150 contacts the second electrode 120 and the terminal board 400. Due to the second electrode tab 150, the terminal board 400 has the same polarity as the second electrode 120.

[0057] In one embodiment, a center pin passing through the center of the electrode assembly 100 in the vertical direction may be located in the central portion of the electrode assembly 100, and the center pin may support the first electrode tab 140 and the second electrode tab 150, but is not limited thereto.

[0058] The housing 200 is connected to the first electrode 110 of the electrode assembly 100 and houses the electrode assembly 100. The housing 200 includes an opening 210 that exposes the upper part of the electrode assembly 100. The bottom of the housing 200 is connected to the first electrode 110 of the electrode assembly 100 through the first electrode tab 140 to have the same polarity as the first electrode 110. In one embodiment, the housing 200 has a cylindrical shape for housing the jelly-roll-shaped electrode assembly 100, but is not limited thereto, and may have any of various known shapes. The housing 200 may house any of various known electrolyte solutions together with the electrode assembly 100. In one embodiment, the outer surface of the housing 200 may be the first electrode terminal of the rechargeable battery 1000, but is not limited thereto. In one embodiment, the outer surface of the flange portion 410, which is the outer surface of the terminal plate 400, may be the second electrode terminal of the rechargeable battery 1000, but is not limited thereto. In one embodiment, a plating layer may be coated on the outer surface of the housing 200, but the present invention is not limited thereto, and any of various known coating layers may be coated on the outer surface of the housing 200.

[0059] The opening 210 of the housing 200 is covered by the cover plate 300 and the terminal plate 400.

[0060] The cover plate 300 is combined with the housing 200 to cover the peripheral area of the opening 210. The cover plate 300 includes a through hole 310 that exposes the central area of the opening 210. In one embodiment, the cover plate 300 is directly connected to the side wall of the housing 200 by a welding process to cover the peripheral area of the opening 210, and the opening 210 of the housing 200 is formed within the side wall of the housing 200. In one embodiment, the cover plate 300 has an annular shape due to the through hole 310 formed in its central portion, but is not limited thereto. The cover plate 300 is combined with the housing 200 to have the same polarity as the first electrode 110. In one embodiment, the cover plate 300 includes stainless steel, but is not limited thereto, and may include a metal such as any one of aluminum, nickel, and copper. In one embodiment, the outer surface of the cover plate 300 may be the first electrode terminal of the rechargeable battery 1000, but is not limited thereto.

[0061] In one embodiment, a plating layer may be coated on the outer surface of the cover plate 300, but the present invention is not limited thereto, and any of various known coating layers may be coated on the outer surface of the cover plate 300.

[0062] The terminal board 400 is connected to the second electrode 120 and is insulatingly coupled to the cover plate 300. The terminal board 400 covers the through hole 310 of the cover plate 300. The terminal board 400 is disposed on the cover plate 300. The terminal board 400 covers the central region of the opening 210 of the housing 200 exposed by the through hole 310 of the cover plate 300. The terminal board 400 covers the central region of the opening 210, the cover plate 300 covers the peripheral region of the opening 210, and thus, the opening 210 of the housing 200 is completely covered by the terminal board 400 and the cover plate 300. The terminal board 400 is coupled to the second electrode tab 150 of the electrode assembly 100 to be connected to the second electrode 120 of the electrode assembly 100. The terminal board 400 has the same polarity as the second electrode 120.

[0063] The terminal board 400 includes a flange portion 410 and a protrusion portion 420.

[0064] The flange portion 410 is disposed on the cover plate 300 and overlaps the cover plate 300 to cover the through hole 310. The flange portion 410 has a larger area than the protrusion portion 420. For example, the flange portion 410 may have a larger diameter than the protrusion portion 420. In one embodiment, the flange portion 410 has a thinner thickness than the protrusion portion 420, but is not limited thereto. The lower surface of the flange portion 410 contacts the heat fusion layer 500, and the flange portion 410 is insulatingly bonded to the cover plate 300 through the heat fusion layer 500. In one embodiment, the outer surface of the flange portion 410 may be the second electrode terminal of the rechargeable battery 1000.

[0065] The protrusion portion 420 protrudes from the flange portion 410 to pass through the through hole 310. The protrusion portion 420 passes through the through hole 310 to be connected to the second electrode 120. The lower surface of the protrusion portion 420 contacts the second electrode tab 150. Since the protrusion portion 420 is coupled to the second electrode tab 150, the protrusion portion 420 and the flange portion 410 of the terminal board 400 have the same polarity as the second electrode 120.

[0066] In one embodiment, the protrusion portion 420 and the flange portion 410 are integrally formed, but are not limited thereto, and in another embodiment, different materials may be combined to form the terminal board 400.

[0067] In one embodiment, a plating layer may be coated on the outer surface of the terminal board 400, but the present invention is not limited thereto, and any of various known coating layers may be coated on the outer surface of the terminal board 400.

[0068] Figure 3 Illustration Figure 2 Cross-sectional view of the region “A” in.

[0069] See Figure 3, in one embodiment, the surface of the protrusion 420 includes a curved surface CS and an inclined surface IS.

[0070] The protrusion 420 includes a curved surface CS extending from the lower surface of the flange portion 410 and an inclined surface IS extending from the curved surface CS to pass through the through hole 310.

[0071] The curved surface CS may have a radius of curvature (e.g., a predetermined radius of curvature), and the inclined surface IS may have a slope (e.g., a predetermined slope).

[0072] In one embodiment, since the protrusion 420 includes a curved surface CS extending from the lower surface of the flange portion 410, a first length L1 between the inclined surface IS and the edge of the through hole 310 is longer than a second length L2 between the curved surface CS and the edge of the through hole 310.

[0073] In one embodiment, the protrusion 420 includes an inclined surface IS that is an inclined straight line extending from the curved surface CS and passing through the through hole 310, and thus, as the surface of the protrusion 420 approaches the end of the inclined surface IS from the curved surface CS, the surface of the protrusion 420 is farther from the edge of the through hole 310.

[0074] Since the protrusion 420 of the terminal plate 400 includes a curved surface CS extending from the lower surface of the flange portion 410 and an inclined surface IS, as the surface of the protrusion 420 approaches the end of the inclined surface IS from the curved surface CS, the surface of the protrusion 420 becomes farther from the edge of the through hole 310, and thus, even if an assembly error occurs in the horizontal direction between the cover plate 300 and the terminal plate 400, it is possible to prevent a short circuit from occurring between the cover plate 300 having the same polarity as the first electrode 110 and the terminal plate 400 having the same polarity as the second electrode 120. The cover plate 300 and the terminal plate 400 may both be electrode terminals.

[0075] In addition, since the protrusion 420 of the terminal plate 400 includes a curved surface CS extending from the surface of the flange portion 410, even if an unexpected pressure is applied to the terminal plate 400, the stress caused by the pressure is dispersed in the curved surface CS of the protrusion 420 extending from the lower surface of the flange portion 410, and thus, it is possible to prevent damage from occurring between the flange portion 410 and the protrusion 420 due to the pressure.

[0076] In addition, since the protrusion 420 of the terminal plate 400 includes the curved surface CS extending from the surface of the flange portion 410, when an accident (such as a short circuit between two electrodes) occurs in the internal space of the rechargeable battery 1000, causing the internal pressure to increase due to the gas GA generated by the increase in the temperature in the internal space of the rechargeable battery 1000, the heat-melt layer 500 can be melted due to the increased temperature and can be discharged to the outside by the internal pressure. As a result, the space between the flange portion 410 and the cover plate 300 is formed as a ventilation channel. At the same time, the gas GA is guided from the internal space of the rechargeable battery 1000 along the curved surface CS of the terminal plate 400 to the space between the flange portion 410 and the cover plate 300, which serves as a ventilation channel, to be discharged to the outside. Therefore, the risk of explosion of the rechargeable battery 1000 can be suppressed.

[0077] The heat-melt layer 500 is disposed between the cover plate 300 and the flange portion 410 of the terminal plate 400 and insulatively bonds the cover plate 300 and the flange portion 410 of the terminal plate 400. The heat-melt layer 500 contains an insulating material and insulates between the cover plate 300 and the terminal plate 400. In one embodiment, the heat-melt layer 500 is heat-fused or laser-beam-fused between the cover plate 300 and the flange portion 410 of the terminal plate 400. The heat-melt layer 500 can include any of various known materials that insulatively bond the cover plate 300 and the terminal plate 400. Since the cover plate 300 and the terminal plate 400 are bonded by the heat-melt layer 500, the opening 210 of the housing 200 that houses the electrode assembly 100 is completely sealed by the cover plate 300, the terminal plate 400, and the heat-melt layer 500.

[0078] In one embodiment, the heat-melt layer 500 is cured by heat but can be melted at a predetermined temperature. In one embodiment, the predetermined temperature at which the heat-melt layer 500 melts can be higher than the temperature used to cure the heat-melt layer 500, but is not limited thereto.

[0079] For example, the heat-melt layer 500 can contain a thermosetting resin and a thermoplastic resin. In one embodiment, the thermosetting resin and the thermoplastic resin of the heat-melt layer 500 can be stacked in multiple layers, but are not limited thereto. The thermosetting resin of the heat-melt layer 500 is cured by heat and can contain any of various known thermosetting resins, such as phenol resin, urea resin, melamine resin, epoxy resin, and polyester resin. In one embodiment, the thermoplastic resin of the heat-melt layer 500 contains a polypropylene resin that melts at a predetermined temperature, but is not limited thereto. In another embodiment, it can contain any of various known thermoplastic resins, such as any polystyrene, polyethylene, and polyvinyl chloride resins.

[0080] As described above, in the rechargeable battery 1000 according to an embodiment, since the protrusion 420 of the terminal plate 400 insulatingly coupled to the cover plate 300 includes a curved surface CS and an inclined surface IS extending from the lower surface of the flange portion 410, as the surface of the protrusion 420 passing through the through hole 310 of the cover plate 300 gets closer to the end of the inclined surface IS from the curved surface CS, the surface of the protrusion 420 becomes farther from the edge of the through hole 310. And thus, even if an assembly error occurs in the horizontal direction between the cover plate 300 and the terminal plate 400, it is possible to suppress a short circuit from occurring between the cover plate 300 having the same polarity as the first electrode 110 and the terminal plate 400 having the same polarity as the second electrode 120. The cover plate 300 and the terminal plate 400 can both be electrode terminals.

[0081] That is, even if an assembly error occurs, a rechargeable battery 1000 that suppresses a short circuit from occurring between two electrode terminals can be provided.

[0082] In addition, in the rechargeable battery 1000 according to an embodiment, since the protrusion 420 of the terminal plate 400, which is an electrode terminal, includes a curved surface CS extending from the lower surface of the flange portion 410, even if an unexpected pressure is applied to the terminal plate 400, the stress caused by the pressure can be dispersed in the curved surface CS of the protrusion 420 extending from the lower surface of the flange portion 410. And thus, it is possible to suppress damage from occurring between the flange portion 410 and the protrusion 420 due to the pressure.

[0083] That is, a rechargeable battery 1000 that can suppress an electrode terminal from being damaged due to pressure is provided.

[0084] In addition, in the rechargeable battery 1000 according to an embodiment, since the protrusion 420 of the terminal plate 400 insulatingly coupled to the cover plate 300 through the heat-melt layer 500 includes a curved surface CS extending from the surface of the flange portion 410, when an unexpected event (such as a short circuit between two electrodes) occurs in the internal space of the rechargeable battery 1000 such that the internal pressure increases due to the gas GA generated by an increase in the temperature in the internal space of the rechargeable battery 1002, the heat-melt layer 500 can be melted due to the increased temperature and can be discharged to the outside by the internal pressure. Thus, a space between the flange portion 410 and the cover plate 300 is formed as a ventilation passage. At the same time, the gas GA can be guided from the internal space of the rechargeable battery 1000 along the curved surface CS of the terminal plate 400 to the space between the flange portion 410 and the cover plate 300, which is the ventilation passage, to be discharged to the outside. And thus, the risk of explosion of the rechargeable battery 1000 can be suppressed.

[0085] That is, even if the temperature and pressure inside the rechargeable battery 1000 increase unexpectedly, the rechargeable battery 1000 can suppress the risk of explosion.

[0086] Herein, reference will be made to Figure 4 and Figure 5 to describe a rechargeable battery 1002 according to another embodiment. Herein, elements different from those of the rechargeable battery according to the above embodiment will be mainly described.

[0087] Figure 4 Illustrate a cross-sectional view of a rechargeable battery according to another embodiment.

[0088] Refer to Figure 4 and a rechargeable battery 1002 according to another embodiment includes an electrode assembly 100, a case 200, a cover plate 300, a terminal plate 400, and a thermal fusion layer 500.

[0089] The terminal plate 400 is connected to the second electrode 120 and is insulatingly coupled to the cover plate 300. The terminal plate 400 covers the through hole 310 of the cover plate 300. The terminal plate 400 is disposed between the cover plate 300 and the electrode assembly 100. The terminal plate 400 covers the central region of the opening 210 of the case 200 exposed by the through hole 310 of the cover plate 300. The terminal plate 400 covers the central region of the opening 210, the cover plate 300 covers the peripheral region of the opening 210, and thus, the opening 210 of the case 200 is completely covered by the terminal plate 400 and the cover plate 300. The terminal plate 400 is coupled to the second electrode tab 150 of the electrode assembly 100 to be connected to the second electrode 120 of the electrode assembly 100. The terminal plate 400 has the same polarity as the second electrode 120.

[0090] The terminal plate 400 includes a flange portion 410 and a protrusion portion 420.

[0091] The flange portion 410 is disposed between the cover plate 300 and the electrode assembly 100 and overlaps with the cover plate 300 to cover the through hole 310. The flange portion 410 has a larger area than the protrusion portion 420. For example, the flange portion 410 may have a larger diameter than the protrusion portion 420. In one embodiment, the flange portion 410 has a thinner thickness than the protrusion portion 420, but is not limited thereto. The upper surface of the flange portion 410 contacts the thermal fusion layer 500, and the flange portion 410 is insulatingly bonded to the cover plate 300 through the thermal fusion layer 500. The flange portion 410 is connected to the second electrode 120. In one embodiment, the lower surface of the flange portion 410 contacts the second electrode tab 150. Since the flange portion 410 is coupled to the second electrode tab 150, the protrusion portion 420 and the flange portion 410 of the terminal plate 400 have the same polarity as the second electrode 120.

[0092] The protrusion 420 protrudes from the flange portion 410 to pass through the through hole 310. The protrusion 420 passes through the through hole 310 to be exposed to the outside of the cover plate 300. In one embodiment, the outer surface of the protrusion 420 can be the second electrode terminal of the rechargeable battery 1002.

[0093] In one embodiment, the protrusion 420 and the flange portion 410 are integrally formed, but are not limited thereto, and in another embodiment, different materials can be combined to form the terminal plate 400.

[0094] The outer surface of the protrusion 420 can be disposed on the same plane as the outer surface of the cover plate 300 or on a plane different from the outer surface of the cover plate 300.

[0095] For example, the height of the outer surface of the protrusion 420 can be the same as the height of the outer surface of the cover plate 300, but is not limited thereto, and the height of the outer surface of the protrusion 420 can be higher or lower than the height of the outer surface of the cover plate 300.

[0096] Figure 5 Illustration Figure 4 Cross-sectional view of the area "B" in.

[0097] See Figure 5 , in one embodiment, the surface of the protrusion 420 includes a curved surface CS and an inclined surface IS.

[0098] The protrusion 420 includes a curved surface CS extending from the upper surface of the flange portion 410 and an inclined surface IS extending from the curved surface CS to pass through the through hole 310.

[0099] The curved surface CS can have a radius of curvature (e.g., a predetermined radius of curvature), and the inclined surface IS can have a slope (e.g., a predetermined slope).

[0100] Since the protrusion 420 includes a curved surface CS extending from the upper surface of the flange portion 410, the first length L1 between the inclined surface IS and the edge of the through hole 310 is longer than the second length L2 between the curved surface CS and the edge of the through hole 310.

[0101] In one embodiment, the protrusion 420 includes an inclined straight inclined surface IS extending from the curved surface CS and passing through the through hole 310, and thus, as the surface of the protrusion 420 approaches the end of the inclined surface IS from the curved surface CS, the protrusion 420 is farther from the edge of the through hole 310.

[0102] Since the protrusion 420 of the terminal plate 400 includes a curved surface CS and an inclined surface IS that extend from the upper surface of the flange portion 410, as the surface of the protrusion 420 gets closer to the end of the inclined surface IS from the curved surface CS, the protrusion 420 becomes farther away from the edge of the through hole 310. And thus, even if an assembly error occurs in the horizontal direction between the cover plate 300 and the terminal plate 400, a short circuit can be suppressed between the cover plate 300 having the same polarity as the first electrode 110 and the terminal plate 400 having the same polarity as the second electrode 120. The cover plate 300 and the terminal plate 400 can both be electrode terminals.

[0103] In addition, since the protrusion 420 of the terminal plate 400 includes a curved surface CS that extends from the upper surface of the flange portion 410, even if an unexpected pressure is applied to the terminal plate 400, the stress caused by the pressure is dispersed in the curved surface CS of the protrusion 420 that extends from the upper surface of the flange portion 410. And thus, damage between the flange portion 410 and the protrusion 420 due to the pressure can be suppressed.

[0104] In addition, since the protrusion 420 of the terminal plate 400 includes a curved surface CS that extends from the surface of the flange portion 410, when an unexpected event (such as a short circuit between two electrodes) occurs in the internal space of the rechargeable battery 1002 such that the internal pressure increases due to the gas GA generated by the increase in temperature in the internal space of the rechargeable battery 1002, the heat-melting layer 500 can be melted due to the increased temperature and can be discharged to the outside by the internal pressure. Thus, the space between the flange portion 410 and the cover plate 300 is formed as a ventilation passage. And at the same time, the internal gas GA can be guided from the internal space of the rechargeable battery 1002 along the curved surface CS of the terminal plate 400 through the space between the flange portion 410 and the cover plate 300 as a ventilation passage to be discharged to the outside. And thus, the risk of explosion of the rechargeable battery 1002 can be suppressed.

[0105] As described above, in the rechargeable battery 1002 according to an embodiment, since the protrusion 420 of the terminal plate 400 that is insulatingly bonded to the cover plate 300 includes a curved surface CS and an inclined surface IS that extend from the upper surface of the flange portion 410, as the surface of the protrusion 420 passing through the through hole 310 of the cover plate 300 gets closer to the end of the inclined surface IS from the curved surface CS, the surface of the protrusion 420 becomes farther away from the edge of the through hole 310. And thus, even if an assembly error occurs in the horizontal direction between the cover plate 300 and the terminal plate 400, a short circuit can be suppressed between the cover plate 300 having the same polarity as the first electrode 110 and the terminal plate 400 having the same polarity as the second electrode 120. The cover plate 300 and the terminal plate 400 can both be electrode terminals.

[0106] That is, even if an assembly error occurs, in the rechargeable battery 1002, a short circuit between the two electrode terminals can be suppressed.

[0107] In addition, in the rechargeable battery 1002 according to an embodiment, since the protruding portion 420 of the terminal plate 400 serving as an electrode terminal includes a curved surface CS extending from the upper surface of the flange portion 410, even if an accidental pressure is applied to the terminal plate 400, the stress caused by the pressure is dispersed in the curved surface CS of the protruding portion 420 extending from the upper surface of the flange portion 410, and thus, damage between the flange portion 410 and the protruding portion 420 due to the pressure can be suppressed.

[0108] That is, the rechargeable battery 1002 that suppresses damage to the electrode terminal due to pressure is provided.

[0109] In addition, in the rechargeable battery 1002 according to an embodiment, since the protruding portion 420 of the terminal plate 400 that is insulatingly bonded to the cover plate 300 through the heat-melting layer 500 includes a curved surface CS extending from the surface of the flange portion 410, when an accidental event (such as a short circuit between the two electrodes) occurs in the internal space of the rechargeable battery 1002 such that the internal pressure increases due to the gas GA generated by the increase in temperature in the internal space of the rechargeable battery 1002, the heat-melting layer 500 can be melted due to the increased temperature and can be discharged to the outside by the internal pressure, so that a space between the flange portion 410 and the cover plate 300 is formed as a ventilation channel, and at the same time, the internal gas GA can be guided from the internal space of the rechargeable battery 1002 along the curved surface CS of the terminal plate 400 through the space between the flange portion 410 and the cover plate 300 serving as the ventilation channel to be discharged to the outside, and thus, the risk of explosion of the rechargeable battery 1002 can be suppressed.

[0110] That is, even if the temperature and pressure inside the rechargeable battery 1002 increase accidentally, in the rechargeable battery 1002, the risk of explosion can be suppressed.

[0111] Although the present invention is described in conjunction with some practical exemplary embodiments currently considered, it should be understood that the present invention is not limited to the disclosed embodiments, but on the contrary, the present invention is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.

Claims

1. A rechargeable battery, comprising: an electrode assembly including a first electrode, a second electrode, and a separator between the first electrode and the second electrode; a housing configured to be connected to the first electrode and accommodate the electrode assembly, and including an opening to receive the electrode assembly; a cover plate configured to be coupled to the housing to cover a peripheral area of the opening, and including a through hole to expose a central area of the opening; and a terminal plate configured to be connected to the second electrode and insulatingly bonded to the cover plate, and including a flange portion covering the through hole and a protrusion protruding from the flange portion to pass through the through hole, wherein the protrusion includes a curved surface extending from a surface of the flange portion, wherein the protrusion further includes an inclined surface extending from the curved surface and passing through the through hole, wherein the flange portion is disposed between the cover plate and the electrode assembly to be connected to the second electrode, wherein the protrusion passes through the through hole to be exposed to the outside of the cover plate, and wherein an open space is defined between the inclined surface and an edge of the through hole such that gas generated within the housing can be discharged to the outside of the housing through the open space.

2. The rechargeable battery according to claim 1, wherein, as a surface of the protrusion is closer to an end of the inclined surface from the curved surface, the surface of the protrusion is farther from the edge of the through hole.

3. The rechargeable battery according to claim 1, further comprising a heat-melt layer between the cover plate and the flange portion and configured to insulatingly bond the cover plate and the flange portion.

4. The rechargeable battery according to claim 3, wherein the heat-melt layer melts at a predetermined temperature.

5. The rechargeable battery according to claim 1, wherein the flange portion is disposed on the cover plate, and the protrusion passes through the through hole to be connected to the second electrode.

6. The rechargeable battery according to claim 1, wherein the flange portion has an area larger than an area of the protrusion.

7. The rechargeable battery according to claim 1, wherein the flange portion has a thickness thinner than a thickness of the protrusion.

8. The rechargeable battery according to claim 1, wherein the flange portion and the protrusion are integrally formed.

9. The rechargeable battery according to claim 1, wherein the housing and the cover plate have the same polarity as the first electrode, and the terminal plate has the same polarity as the second electrode.

10. The rechargeable battery according to claim 1, wherein the electrode assembly further comprises: a first electrode tab extending from the first electrode to be coupled to the housing; and a second electrode tab extending from the second electrode to be coupled to the terminal plate.

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