Rechargeable battery

Abstract

A rechargeable battery according to an exemplary embodiment of the present invention includes: an electrode assembly including a first electrode, a second electrode, and a separator located between the first electrode and the second electrode; a case having an internal space for accommodating the electrode assembly and an opening with one open side; a cover plate coupled to the opening of the case and having a terminal hole exposing the internal space; and an electrode terminal electrically connected to the electrode assembly through the terminal hole and overlapping the cover plate, wherein the separator has a width greater than that of the first electrode and the second electrode, and the separator contacts an inner bottom surface of the case.

Description

Technical Field

[0001] The present invention relates to a rechargeable battery. More particularly, the present invention relates to an ultra-small rechargeable battery Background Art

[0002] Unlike primary batteries that cannot be recharged, rechargeable batteries can be repeatedly charged and discharged. Low-capacity rechargeable batteries have been used in small electronic devices such as mobile phones, laptops, and cameras, and large-capacity batteries have been widely used as power sources for driving motors of hybrid vehicles.

[0003] Typical rechargeable batteries include nickel-cadmium (Ni-Cd) batteries, nickel-metal hydride (Ni-MH) batteries, lithium (Li) batteries, and lithium-ion (Li-ion) rechargeable batteries. In particular, the operating voltage of lithium-ion secondary batteries is about three times higher than that of nickel-cadmium batteries or nickel-metal hydride batteries, which are mainly used as power sources for portable electrical devices. In addition, lithium-ion secondary batteries are widely used in aspects of high energy density per unit weight.

[0004] In particular, as the demand for wearable devices such as headphones, earphones, smart watches, and body-mounted medical devices using Bluetooth increases, the need for high energy density and ultra-small rechargeable batteries is also increasing.

[0005] Such an ultra-small rechargeable battery is small in size, and thus the capacity of the rechargeable battery varies greatly depending on the structure inside a case. Summary of the invention

[0006] Therefore, the present disclosure is directed to providing a rechargeable battery which improves the capacity of the rechargeable battery by minimizing the internal structure of a case of the rechargeable battery.

[0007] A rechargeable battery according to an exemplary embodiment of the present invention includes: an electrode assembly including a first electrode, a second electrode, and a separator located between the first electrode and the second electrode; a case having an internal space for accommodating the electrode assembly and an opening with one open side; a cover plate coupled to the opening of the case and having a terminal hole exposing the internal space; and an electrode terminal electrically connected to the electrode assembly through the terminal hole and overlapping the cover plate, wherein the separator has a width greater than that of the first electrode and the second electrode, and the separator contacts an inner bottom surface of the case.

[0008] The invention may further include a first electrode tab electrically connecting the first electrode and the inner bottom surface of the case; and a second electrode tab electrically connecting the second electrode and the electrode terminal.

[0009] It may further include a first tape attached to the lower surface of the second electrode tab with an area larger than that of the second electrode tab to insulate between the second electrode tab and the electrode assembly; and a second tape attached along the outer peripheral surface in the diameter direction of the electrode assembly and wrapped around the outer side of the electrode assembly to insulate between the outer side of the electrode assembly and the inner side of the shell.

[0010] An insulating disk may be further included, which is located between the second electrode tab and a top surface of the electrode assembly and insulates between the electrode terminal and the electrode assembly.

[0011] An insulating gasket may be further included, which is located between the second electrode tab and the cap plate and insulates between the second electrode tab and the cap plate, and the insulating gasket may have a portion removed corresponding to the electrode terminal.

[0012] The cover plate may be welded to the housing, and the cover plate and the housing may be made of the same metal.

[0013] The electrode terminal may include a flange portion covering the terminal hole and overlapping the cap plate; and a protrusion portion integrally formed with the flange portion and protruding from the flange portion toward the terminal hole.

[0014] The outer side of the protrusion may have a curved surface and an inclined surface, the distance from the curved surface to the end of the cover plate exposed to the terminal hole is shorter than the distance from the inclined surface to the end of the cover plate exposed to the terminal hole, and the distance from the end of the cover plate exposed to the terminal hole toward the end of the inclined surface may be longer.

[0015] A heat-melting layer may be further included between the cover plate and the flange portion and insulatively bonded between the cover plate and the flange portion.

[0016] The heat-fusible layer may be melted at a predetermined temperature.

[0017] In the present invention, without installing an insulating member between the lower surface of the electrode assembly and the case, a rechargeable battery in which a short circuit between the lower surface of the electrode assembly and the case is prevented and the capacity of the rechargeable battery is maximized can be provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 is a perspective view showing a rechargeable battery according to an exemplary embodiment of the present invention.

[0019] Figure 2 is along Figure 1 Cross-sectional view taken along line Ⅱ-Ⅱ.

[0020] Figure 3 : is a view for explaining an attached state of a first band according to an exemplary embodiment of the present invention.

[0021] Figure 4 yes Figure 2 Cross-sectional view of portion A of FIG.

[0022] Figure 5 is a cross-sectional view illustrating a rechargeable battery according to another exemplary embodiment of the present invention.

[0023] Figure 6 yes Figure 5 A cross-sectional view of portion B of FIG. DETAILED DESCRIPTION

[0024] The present invention will be described more fully hereinafter with reference to the accompanying drawings, in which exemplary embodiments of the present invention are shown. As those skilled in the art will appreciate, the described embodiments can be modified in various different ways, all without departing from the scope of the present invention.

[0025] In addition, unless explicitly described to the contrary, the word “comprise” and variations such as “comprising” or “including” will be understood to imply the inclusion of stated elements but not the exclusion of any other elements.

[0026] Hereinafter, a rechargeable battery according to exemplary embodiments is described with reference to the accompanying drawings.

[0027] The rechargeable battery as an ultra-small rechargeable battery according to an exemplary embodiment of the present invention may be a coin type battery (coin cell) or a button type battery (button cell), but is not limited thereto, and may be a cylindrical or pin type battery.

[0028] Here, the coin type battery or button type battery is a thin coin 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.

[0029] Since the coin cell or button cell is mainly cylindrical, the horizontal cross section is circular, but the present invention is not limited thereto, and the horizontal cross section may be elliptical or polygonal. In this case, the diameter is determined as the maximum distance of the outer circumference of the shell (or housing) based on the horizontal direction of the battery, and the height is determined as the maximum distance based on the vertical direction of the battery (the distance from the flat bottom cross section to the flat top cross section).

[0030] Figure 1 is a perspective view showing a rechargeable battery according to an exemplary embodiment of the present invention, Figure 2 is along Figure 1 A cross-sectional view taken along line II-II, and Figure 3: is a view for explaining an attached state of a first band according to an exemplary embodiment of the present invention.

[0031] refer to Figure 1 and Figure 2 , a rechargeable battery 1000 according to an exemplary embodiment of the present invention includes an electrode assembly 100, a case 200 having an inner space for accommodating the electrode assembly 100, a cap plate 300 coupled to the case 200 and sealing the inner space, and an electrode terminal 400 passing through the cap plate and electrically connected to the electrode assembly 100.

[0032] A lower surface of the electrode assembly 100 faces the inner bottom surface of the case 200 , and an upper surface of the electrode assembly 100 faces a lower surface of the cap plate 300 covering the opening 21 of the case 200 .

[0033] The electrode assembly 100 includes a first electrode 11, a second electrode 12, and a separator 13, and the first electrode 11 and the second electrode 12 are respectively located at both sides of the separator 13 which is an electrical insulating material.

[0034] The first electrode 11 includes an electrode active area and an electrode uncoated area, the electrode active area is an area where an active material is coated on a thin plate formed of a long strip-shaped metal foil, the electrode uncoated area is an area where the active material is not coated, and the first electrode terminal 14 can be connected to the electrode uncoated area.

[0035] The electrode uncoated region may be formed at the opposite end relative to the electrode active portion, that is, at both ends in the length direction of the first electrode 11, but is not limited thereto, and the electrode uncoated region may be formed at one end. The first electrode 11 may be a negative electrode, and an active material such as graphite or carbon may be applied to a metal foil such as copper or nickel for the electrode active region.

[0036] The first electrode tab 14 is electrically connected to the electrode uncoated region of the first electrode 11 of the electrode assembly 100, protrudes from the electrode assembly 100, and is welded to the bottom surface of the case 200 to electrically connect the first electrode 11 and the case 200. Accordingly, the case 200 connected to the first electrode tab 14 has the same polarity as the first electrode 11.

[0037] The second electrode 12 includes an electrode active region where the active material is coated on a thin plate formed of a long strip-shaped metal foil and an electrode uncoated region where the active material is not coated, and a second electrode tab 15 may be connected to the electrode uncoated region.

[0038] The electrode uncoated region may be formed at the opposite end with respect to the electrode active portion, that is, at both ends in the length direction of the second electrode 12 , but is not limited thereto, and may be formed at one end.

[0039] The second electrode tab 15 may be connected to the electrode uncoated region of the second electrode 12, and the second electrode tab 15 may protrude from the second electrode 12 to be electrically connected to the electrode terminal 400. The second electrode tab 15 is made of a conductive material such as nickel or copper, and may be connected to the electrode uncoated region by welding. In this case, the welding may be laser welding.

[0040] The second electrode 12 may be a positive electrode, and in an electrode active region, an active material such as a transition metal oxide may be coated on a metal foil such as aluminum.

[0041] The second electrode tab 15 is electrically connected to the electrode uncoated region of the second electrode 12 of the electrode assembly 100, protrudes from the electrode assembly 100, and is welded to the lower surface of the electrode terminal 400 to electrically connect the second electrode 12 and the electrode terminal 400. Through the second electrode tab 15, the electrode terminal 400 has the same polarity as the second electrode 12.

[0042] The separator 13 is located between the first electrode 11 and the second electrode 12, and serves to prevent a short circuit therebetween and enable movement of lithium ions. The separator 13 may be made of, for example, polyethylene, polypropylene, or a composite film of polyethylene and polypropylene.

[0043] The width of the separator 13 may be equal to or greater than the widths of the first and second electrodes 11 and 12, and the width of the first electrode 11 may be greater than the width of the second electrode 12. In this case, the width is the length in the direction in which the electrode assembly is inserted into the case.

[0044] Since the length of the separator 13 is relatively greater than the lengths of the first electrode 11 and the second electrode 12 , the separator 13 may directly contact the inner bottom surface of the case 200 .

[0045] In this way, the width of the separator 13 is formed to be greater than the width of the first electrode 11 or the second electrode 12, thereby preventing the ends of the shell 200 electrically connected to the inner bottom surface of the first electrode 11 and the second electrode of different polarities from contacting each other and short-circuiting even if a separate insulating member or insulating plate is not located between the electrode assembly 100 and the inner bottom surface of the shell 200.

[0046] In addition, when misalignment of the separator 13 occurs, the first electrode 11 having a relatively large width may protrude from the separator 13. The first electrode 11 is electrically connected to the case 200 through the first electrode tab 14, and even if the first electrode 11 protrudes from the separator 13 and contacts the case 200, a short circuit phenomenon does not occur because they have the same polarity.

[0047] The electrode assembly 100 may have a jelly roll shape by being wound around a rotation axis in a state where the first electrode 11, the separator 13, and the second electrode 12 overlap, but is not limited thereto, and the electrode assembly 100 may have a structure in which a sheet-type first electrode, a separator, and a second electrode are repeatedly stacked (not shown).

[0048] The electrode assembly 100 may be insulated by the insulating tape 600 without contacting the inner surface of the case 200 .

[0049] The insulating tape 600 includes a first tape 61 attached to the second electrode tab 15 and a second tape 62 surrounding the electrode assembly 100 .

[0050] The first tape 61 may extend from one end where the second electrode tab 15 is attached to the electrode uncoated region of the second electrode to the other end where the second electrode tab 15 is attached to the electrode terminal 400 (refer to Figure 3 ), and may be attached to the lower surface of the second electrode tab 15 with an area wider than that of the second electrode tab 15.

[0051] The first tape 61 prevents the lower surface of the second electrode tab 15 from contacting and short-circuiting with the end of the first electrode that may be exposed to the upper portion of the electrode assembly 100 .

[0052] The second tape 62 is attached along the diameter direction outer circumferential surface of the electrode assembly 100 to cover the outside of the electrode assembly 100. The second tape 62 electrically insulates between the outer circumferential surface of the electrode assembly 100 and the inner surface of the case 200 while protecting the outside of the electrode assembly 100.

[0053] An insulating gasket 63 may be further installed between the upper surface of the second electrode tab 15 and the cap plate 300 to prevent the second electrode tab 15 or the second electrode 12 and the lower surface of the cap plate 300 from contacting and short-circuiting each other.

[0054] The insulating gasket 63 overlaps the edge of the electrode assembly 100 and is located on the upper surface of the second electrode tab 15 exposed toward the cap plate 300. Since the electrode terminal 400 is connected to the second electrode tab 15, the central portion of the insulating gasket 63 corresponding to the electrode terminal 400 may be removed to expose the center (or center pin) of the electrode assembly.

[0055] In addition, on one side of the electrode assembly 100 adjacent to the cap plate 300, an insulating disk 64 may be further installed to prevent the end of the first electrode 11 and the electrode terminal 400 from short-circuiting by contacting each other. The insulating disk 64 may overlap most of the top surface of the electrode assembly 100.

[0056] A center pin 50 passing through the center of the electrode assembly 100 in a vertical direction may be positioned at the center of the electrode assembly 100 , and the center pin may support the first and second electrode tabs 14 and 15 .

[0057] The housing 200 has a space for accommodating the electrode assembly 100 and the electrolyte solution, has an opening 21 with one side open, and the electrode assembly 100 is inserted through the opening 21 to be accommodated in the inner space of the housing 200. The housing 200 may be in a cylindrical shape with a low height, but is not limited thereto, and may have various well-known shapes. The housing 200 may accommodate a variety of known electrolyte solutions as well as the electrode assembly 100, and the housing 200 may be made of stainless steel.

[0058] An inner bottom surface of the case 200 is connected to the first electrode 11 of the electrode assembly 100 through the first electrode tab 14 , and the case 200 has the same polarity as the first electrode 11 .

[0059] An outer surface of the case 200 may be a first electrode terminal of the rechargeable battery 1000 , and an outer surface of the electrode terminal 400 may be a second electrode terminal of the rechargeable battery 1000 .

[0060] The cap plate 300 and the electrode terminal 400 closing and sealing the inner space of the case 200 may be coupled to the opening 21 of the case 200 , and the cap plate 300 may be coupled to the opening 21 by welding.

[0061] The cap plate 300 is formed in a shape corresponding to the opening 21 , and a step portion 30 may be formed in the opening 21 , so that the cap plate 300 may be easily seated.

[0062] The terminal hole 31 is formed at the center of the cap plate 300, and the terminal hole 31 corresponds to the center of the electrode assembly 100 and exposes the upper portion of the electrode assembly 100. Due to the terminal hole 31 formed at the center, the cap plate 300 has a ring shape.

[0063] The cap plate 300 is combined with the case 200 and has the same polarity as the first electrode 11, and an outer surface of the cap plate 300 may be a first electrode terminal of the rechargeable battery 1000. The cap plate 300 includes stainless steel, but is not limited thereto, and may include metals such as aluminum, nickel, and copper.

[0064] The electrode terminal 400 may be coupled in a state where it is insulated from the cap plate 300 of a different polarity and electrically connected to the second electrode 12 of the electrode assembly through the terminal hole 31 of the cap plate 300. Therefore, the electrode terminal 400 may be a second electrode terminal of the rechargeable battery 1000.

[0065] The electrode terminal 400 may include stainless steel, but is not limited thereto, and the electrode terminal 400 may include metal such as aluminum, nickel, and copper.

[0066] The case 200 and the cap plate 300 may be connected to the first electrode 11 being a negative electrode so that the first electrode terminal is a negative terminal, and the electrode terminal 400 is electrically connected to the second electrode 12 being a positive electrode so that the second electrode terminal may be a positive terminal.

[0067] Meanwhile, the electrode terminal 400 includes a flange portion 41 and a protrusion 42, the flange portion 41 may have a larger area (or diameter) than the protrusion 42, and the flange portion 41 may have a smaller thickness than the protrusion 42. The protrusion 42 and the flange portion 41 may be integrally formed.

[0068] The protrusion 42 of the electrode terminal 400 is inserted into the terminal hole 31 and covers the terminal hole 31 of the cap plate 300 together with the flange portion 41 to seal the inside of the case 200. The protrusion 42 of the electrode terminal 400 is electrically connected to the second electrode tab 15 of the electrode assembly 100, so that the electrode terminal 400 has the same polarity as the second electrode 12. The outer surface of the flange portion 41 may be the second electrode terminal of the rechargeable battery 1000.

[0069] Figure 4 It is shown Figure 2 Cross-sectional view of portion A of FIG.

[0070] refer to Figure 4 The outer surface of the protrusion 42 includes a curved surface CS and an inclined surface IS. The protrusion 42 includes the curved surface CS extending from the lower surface of the flange portion 41 and the inclined surface IS extending from the curved surface CS and passing through the terminal hole 31 .

[0071] The curved surface CS may have a predetermined radius of curvature, and the inclined surface IS may have a predetermined inclination. Accordingly, the surface of the protrusion 42 is away from the end of the curved surface CS toward the end of the inclined surface IS, which is exposed through the terminal hole 31 of the cap plate 300. In this way, if the inclined surface IS is formed, the distance of the protrusion 42 between the cap plate 300 and the electrode terminal 400 in the horizontal direction increases, and even if an alignment error occurs, the occurrence of a short circuit between the cap plate 300 and the protrusion 42 of different polarities can be suppressed.

[0072] Reference again Figure 1 and Figure 2 , the lower surface of the flange portion 41 of the electrode terminal 400 may be attached to one surface of the cap plate 300 by the hot melt layer 500. By combining the hot melt layer 500 between the cap plate 300 and the electrode terminal 400, the opening 21 of the case 200 accommodating the electrode assembly 100 is completely sealed by the cap plate 300, the electrode terminal 400, and the hot melt layer 500.

[0073] The heat fusion layer 500 may be heat-fused between the cap plate 300 and the flange portion 41 of the electrode terminal 400 by using heat or a laser beam.

[0074] The heat melt layer 500 is made of an insulating material to insulate between the electrode terminal 400 and the cap plate 300. The heat melt layer 500 may include various known materials for insulation and bonding between the cap plate 300 and the electrode terminal 400.

[0075] The hot melt layer 500 is cured by heat and may be melted at a predetermined temperature. Here, the predetermined temperature at which the hot melt layer 500 melts may be a temperature exceeding a thermal curing temperature of the hot melt layer 500, but is not limited thereto.

[0076] For example, the hot melt layer 500 may include a thermosetting resin and a thermoplastic resin. The thermosetting resin and the thermoplastic resin of the hot melt layer 500 may be stacked in a plurality of layers, but the present invention is not limited thereto. The thermosetting resin of the hot melt layer 500 is cured by heat, and may include various known thermosetting resins, such as phenol resin, urea resin, melamine resin, epoxy resin, and polyester resin. The thermoplastic resin of the hot melt layer 500 includes a polypropylene resin that melts at a predetermined temperature, but is not limited thereto, and may include various known thermoplastic resins, such as polystyrene, polyethylene, and polyvinyl chloride resins.

[0077] As such, the heat melt layer 500 is melted at a predetermined temperature, and the portion where the heat melt layer 500 is removed becomes a ventilation channel for exhausting gas.

[0078] When an unexpected event (short circuit of two electrodes, etc.) occurs in the internal space of the rechargeable battery 1000, the temperature rises, the hot melt layer 500 melts due to the increased temperature, and the volume is reduced, and a ventilation channel is formed for the gas GA generated inside the rechargeable battery to be discharged to the outside. The internal gas is guided from the internal space of the rechargeable battery 1000 along the curved surface CS of the electrode terminal 400 to the space between the flange portion 41 and the cap plate 300 as a ventilation channel, and is quickly discharged to the outside, thereby suppressing the risk of explosion of the rechargeable battery 1000.

[0079] Figure 5 is a cross-sectional view showing a rechargeable battery according to another exemplary embodiment of the present invention, and Figure 6 yes Figure 5 A cross-sectional view of portion B of FIG.

[0080] Figure 5 and Figure 6 A rechargeable battery 1002 according to another exemplary embodiment of the present invention is shown in FIG. Figures 1 to 3 The rechargeable batteries of are largely identical, so only the other parts are described in detail.

[0081] refer to Figure 5 , a rechargeable battery 1002 according to another exemplary embodiment of the present invention includes an electrode assembly 100 , a case 200 , a cap plate 300 , an electrode terminal 400 , and a hot melt layer 500 .

[0082] The electrode terminal 400 is electrically connected to the second electrode 12, and is insulated and bonded to the cap plate 300 by the heat-melting layer 500. The electrode terminal 400 covers the terminal hole 31 of the cap plate 300. The electrode terminal 400 is located between the cap plate 300 and the electrode assembly 100.

[0083] The electrode terminal 400 covers the central area of ​​the opening 21 of the case 200, through which the terminal hole 31 of the cap plate 300 is exposed. Since the electrode terminal 400 covers the central area of ​​the opening 21 and the cap plate 300 covers the outer area of ​​the opening 21, the opening 21 of the case 200 is completely sealed by the electrode terminal 400 and the cap plate 300. The electrode terminal 400 is connected to the second electrode tab 15 of the electrode assembly 100, and is electrically connected to the second electrode 12 of the electrode assembly 100.

[0084] The electrode terminal 400 includes a flange portion 41 and a protrusion 42. The flange portion 41 is located between the cap plate 300 and the electrode assembly 100 in the case 200, and overlaps the cap plate 300 to cover the terminal hole 31.

[0085] The upper surface of the flange portion 41 contacts the hot melt layer 500, and the flange portion 41 is insulated and bonded to the cap plate 300 by the hot melt layer 500. The lower surface of the flange portion 41 is electrically connected to the second electrode tab 15. Since the flange portion 41 is connected to the second electrode tab 15, the protrusion 42 of the electrode terminal 400 and the flange portion 41 have the same polarity as the second electrode 12.

[0086] The protrusion 42 passes through the terminal hole 31 and is exposed to the outside of the case 200. An outer surface of the protrusion 42 may be a second electrode terminal of the rechargeable battery 1002.

[0087] The outer surface of the protrusion 42 may be located on the same plane as the outer surface of the cover plate 300 or on a different plane from the outer surface of the cover plate 300. For example, the height of the outer surface of the protrusion 42 may 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 42 may be higher or lower than the height of the outer surface of the cover plate 300.

[0088] The outer side of the protrusion 42 includes a curved surface CS and an inclined surface IS.

[0089] The protrusion 42 includes a curved surface CS extending from the lower surface of the flange portion 41 and an inclined surface IS extending from the curved surface CS and passing through the terminal hole 31 .

[0090] The curved surface CS may have a predetermined radius of curvature, and the inclined surface IS may have a predetermined inclination. Therefore, the surface of the protrusion 42 is away from the cap plate 300, which is the edge of the terminal hole 31, from the curved surface CS toward the end of the inclined surface IS. In this way, if the inclined surface IS is formed, the distance of the protrusion 42 between the cap plate 300 and the electrode terminal 400 in the horizontal direction increases, and even if an alignment error occurs, the occurrence of a short circuit between the cap plate 300 and the protrusion 42 of different polarities can be suppressed.

[0091] In this way, when the flange portion 41 is connected by the heat-melting portion 500 in the housing 200, if the temperature in the housing 200 rises due to the occurrence of an event and the heat-melting portion 500 melts, the flange portion 41 is separated from the cap plate 300 and moves in the gravity direction, so that the terminal hole 31 can be opened. Figure 1 The gas is discharged to the outside faster to prevent explosion.

[0092] While the invention has been described in conjunction with what are presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments. On the contrary, the invention is intended to cover various modifications and equivalent arrangements included within the scope of the appended claims.

[0093] Description of labels:

[0094] 11: First electrode 12: Second electrode

[0095] 13: Partition 30: Step

[0096] 41: flange 42: protrusion

[0097] 100: Electrode assembly 200: Shell

[0098] 300: Cover plate 400: Electrode terminal

[0099] 500: Hot melt layer

Claims

1. A rechargeable battery comprising: An electrode assembly comprising a first electrode, a second electrode, and a separator located between the first electrode and the second electrode; a housing having an inner space for accommodating the electrode assembly and an opening with an open side; a cover plate coupled to the opening of the housing and having a terminal hole exposing the internal space; and an electrode terminal, electrically connected to the electrode assembly through the terminal hole and overlapping the cap plate, wherein the separator has a width greater than that of the first electrode and the second electrode, and the separator is in contact with an inner bottom surface of the housing, wherein the rechargeable battery further comprises a first electrode tab electrically connecting the first electrode and the inner bottom surface of the housing, wherein the width of the first electrode is greater than the width of the second electrode, and The width is a length in a direction along which the electrode assembly is inserted into the case.

2. The rechargeable battery according to claim 1, further comprising: The second electrode connecting piece electrically connects the second electrode and the electrode terminal.

3. The rechargeable battery according to claim 2, further comprising: a first tape attached to a lower surface of the second electrode tab with a larger area than the second electrode tab to insulate between the second electrode tab and the electrode assembly; and A second tape is attached along a diameter-direction outer peripheral surface of the electrode assembly and is wrapped around the outer side of the electrode assembly to insulate between the outer side of the electrode assembly and the inner side of the case.

4. The rechargeable battery according to claim 2, further comprising: An insulating disk is located between the second electrode tab and a top surface of the electrode assembly and insulates between the electrode terminal and the electrode assembly.

5. The rechargeable battery according to claim 2, further comprising: an insulating gasket, located between the second electrode terminal tab and the cover plate, and insulating between the second electrode terminal tab and the cover plate, Wherein, the insulating gasket has a portion removed corresponding to the electrode terminal.

6. The rechargeable battery according to claim 1, wherein: The cover plate is welded to the housing, and The cover plate and the housing are made of the same metal.

7. The rechargeable battery according to claim 1, wherein: The electrode terminal comprises: a flange portion covering the terminal hole and overlapping the cover plate; and The protrusion is formed integrally with the flange portion and protrudes from the flange portion toward the terminal hole.

8. The rechargeable battery according to claim 7, wherein: The outer side of the protrusion has a curved surface and an inclined surface, and the distance from the curved surface to the end of the cover plate exposed to the terminal hole is shorter than the distance from the inclined surface to the end of the cover plate exposed to the terminal hole, and A distance from an end portion of the cap plate exposed to the terminal hole toward an end portion of the inclined surface becomes longer.

9. The rechargeable battery according to claim 7, further comprising: The hot melt layer is located between the cover plate and the flange portion and is insulated and bonded between the cover plate and the flange portion.

10. The rechargeable battery according to claim 9, wherein The heat-fusible layer melts at a predetermined temperature.

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