Rechargeable battery

Abstract

A rechargeable battery includes: a case that receives an electrode assembly and includes an opening; a cover assembly that includes a cover plate coupled to the case and covering the opening and a terminal plate coupled to the cover plate; and an outer shell that covers the cover plate and is coupled to the case, and an outer surface of the terminal plate protrudes further than an outer surface of the outer shell to have a height difference.

Description

Technical Field

[0001] Aspects of embodiments of the present invention relate to rechargeable batteries. Background Art

[0002] Unlike primary batteries, which cannot be recharged, rechargeable batteries can be repeatedly charged and discharged. Low-capacity rechargeable batteries are used in portable small electronic devices such as mobile phones, notebook computers, and camcorders. Large-capacity batteries are widely used as power sources for driving motors such as for hybrid vehicles.

[0003] Representative 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, lithium-ion rechargeable batteries have an operating voltage about three times higher than that of nickel-cadmium batteries or nickel-metal hydride batteries, which are mainly used as power sources for portable electronic devices. In addition, lithium-ion rechargeable batteries are widely used because of their high energy density per unit weight.

[0004] In particular, as the demand for wearable devices such as headphones using Bluetooth, in-ear headphones, smart watches, and body-attached medical devices increases, the demand for rechargeable batteries that are high in energy density and ultra-small is increasing.

[0005] An ultra-small rechargeable battery has aspects of securing a required electric capacity within a limited size, achieving an effective structure while improving effective low weight, and improving structural stability.

[0006] The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art. Summary of the invention

[0007] According to one aspect of an embodiment of the present invention, an ultra-small rechargeable battery is provided. According to one aspect of an embodiment of the present invention, a rechargeable battery that can prevent reverse insertion when inserted into a set and can prevent external short circuits of parts with different polarities (e.g., a terminal plate and a cap plate or a housing) is provided.

[0008] According to another aspect of an embodiment of the present invention, a rechargeable battery is provided in which a terminal plate and a case having different polarities can smoothly contact a pack when inserted into the pack.

[0009] According to one or more embodiments of the present invention, a rechargeable battery includes: a shell that receives an electrode assembly and includes an opening; a cover assembly that includes a cover plate coupled to the shell and covering the opening and a terminal plate coupled to the cover plate; and an outer shell that covers the cover plate and is coupled to the shell, wherein an outer surface of the terminal plate protrudes further than an outer surface of the outer shell to have a height difference.

[0010] The electrode assembly may include a first electrode, a second electrode, and a separator between the first electrode and the second electrode, the case may be connected to the first electrode through a first electrode tab, and the terminal plate may be connected to the second electrode through a second electrode tab.

[0011] The cap plate may be electrically connected to the case, and the cap plate and the terminal plate may be thermally fused with a thermally fused member therebetween and may be electrically insulated from each other.

[0012] The terminal plate may include: a flange portion, which is arranged between the cover plate and the electrode assembly, and is electrically insulated from and attached to the inner surface of the cover plate; and a protruding terminal, which protrudes from the center of the flange portion to the outside, passes through the terminal hole of the cover plate and the through hole of the outer shell, and is electrically connected to the second electrode tab through the inner surface of the terminal plate, and the protruding terminal may protrude more than the outer surface of the outer shell by a first height difference to form the outer surface of the rechargeable battery.

[0013] The housing may include: a plane portion covering an outer surface of the cover plate; and a side portion extending along a side surface of the housing at an outer side of the plane portion to cover a portion of the side surface of the housing and coupled to the side surface of the housing.

[0014] The housing may be formed of an electrically insulating material to prevent an electrical short circuit between outer surfaces of the protruding terminals and the outer surface of the cap plate.

[0015] The through hole of the housing may be concentric with the terminal hole of the cap plate, and an inner diameter of the through hole may be greater than an outer diameter of the protruding terminal.

[0016] The inner diameter of the housing may be larger than the sum of the outer diameter of the protruding terminal and twice the diameter-direction distance of the planar portions disposed on both sides of the protruding terminal in the diameter direction.

[0017] The shell may include PP, PE, PET, PEN resin or rubber.

[0018] The terminal plate may include: a flange portion, which is on the outer surface of the cover plate and is electrically insulated from and attached to the outer surface of the cover plate; and a tab connection portion, which protrudes inward from the center of the flange portion and protrudes toward the electrode assembly through the through hole of the outer shell and the terminal hole of the cover plate, and is electrically connected to the second electrode tab through the inner surface of the tab connection portion, and the flange portion may protrude more than the outer surface of the outer shell by a second height difference to form the outer surface of the rechargeable battery.

[0019] The housing may include: a planar portion, including a through hole having an inner diameter larger than an outer diameter of the flange portion to cover the exposed surface of the cover plate while exposing the flange portion; and a side portion, extending along the side of the shell on the outside of the planar portion to cover a portion of the side of the shell and connected to the side of the shell.

[0020] The inner diameter of the housing may be larger than the sum of the outer diameter of the flange portion and twice the diameter-direction distance of the planar portions disposed on both sides of the flange portion in the diameter direction.

[0021] The housing may form a step on a side surface of the casing.

[0022] The housing may define a first diameter in a diametrical direction at a lower portion of the shell, and the shell may be coupled to an upper portion of the housing and define a second diameter greater than the first diameter in a diametrical direction.

[0023] As described above, the rechargeable battery according to one or more embodiments of the present invention forms a step on the side of the shell because the shell covers the cover plate and is connected to the shell. In other words, since the shell protrudes more than the side of the shell at the cover plate and its adjacent side, a step with increased height or diameter can be formed. Therefore, visually or structurally, the rechargeable battery can be effectively prevented from being reversely inserted into the kit.

[0024] In a rechargeable battery according to one or more embodiments, two parts (e.g., a cap plate and a terminal plate) having different polarities in a cap assembly are exposed in the same direction, and a shell can cover at least one of the two parts having different polarities. When the shell is formed of an electrically insulating material, external short circuit of the two parts through conductive particles can be effectively prevented.

[0025] Further, since the rechargeable battery according to one or more embodiments combines the outer case to the housing, the outer case serves as a buffer for physical impact, so that safety in a drop test and a tumble test may be improved.

[0026] In the rechargeable battery according to one or more embodiments, although the outer case is applied, the terminal plate is more protruded than the outer case, so that when inserted into the pack, the terminal plate and the case can smoothly contact the pack. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 is a perspective view of a rechargeable battery according to an embodiment of the present invention.

[0028] Figure 2 for Figure 1 An exploded perspective view of a rechargeable battery.

[0029] Figure 3 For along Figure 1 A cross-sectional view taken along line III-III in FIG.

[0030] Figure 4 is a perspective view of a rechargeable battery according to an embodiment of the present invention.

[0031] Figure 5 for Figure 4 An exploded perspective view of a rechargeable battery.

[0032] Figure 6 For along Figure 4 A cross-sectional view taken along line VI-VI in FIG.

[0033] Description of Reference Numerals

[0034] 1, 2: Rechargeable battery 10: Electrode assembly

[0035] 11: First electrode 12: Second electrode

[0036] 13: Partition 14: Insulation sheet

[0037] 20: Shell 21: Opening

[0038] 30, 60: Cover assembly 31: Cover plate

[0039] 33, 63: Terminal board 34: Hot melt component

[0040] 40, 70: housing 41, 71: flat surface

[0041] 42, 72: Side 51: First electrode terminal piece

[0042] 52: second electrode tab 61, 62: insulating member

[0043] 611, 621: through hole 101: first end

[0044] 102: second end 301: exposed surface

[0045] 311: Terminal hole 331, 631: Flange

[0046] 332, 632: protruding terminal 341: through hole

[0047] 411, 711: Through hole D: Battery diameter

[0048] D1, D2: inner diameter D11, D21: outer diameter

[0049] D12, D22: Diameter distance H: Height

[0050] H1, H2: Length in height direction G1, G2: First gap, second gap

[0051] P1, P3: expansion part P2, P4: non-expansion part

[0052] ΔH1, ΔH2: first height difference, second height difference DETAILED DESCRIPTION

[0053] 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 will be appreciated by those skilled in the art, the described embodiments may be modified in various ways without departing from the scope of the present invention. The accompanying drawings and descriptions are to be regarded as illustrative and non-restrictive in nature. Similar reference numerals refer to similar elements throughout the specification.

[0054] In addition, unless explicitly described to the contrary, it should be understood that terms such as "include", "comprises" or "has" used in this specification indicate the existence of the features, numbers, steps, operations, components, parts and / or their combinations, but do not preclude the existence or addition of one or more other features, numbers, steps, operations, components, parts or their combinations.

[0055] Further, in the present specification, it should be understood that when a component is referred to as being “connected” or “coupled” to another component, it may be directly connected or coupled to the other component or connected or coupled to the other component with one or more other components interposed therebetween.

[0056] Unless the context clearly indicates otherwise, singular forms shall include plural forms.

[0057] It should be understood that although the terms "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 element. 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 present invention. Unless the context clearly indicates otherwise, a term in the singular may include a plural form.

[0058] In addition, terms such as "below", "lower", "above", "upper", etc. are used to describe the relationship of the configurations shown in the drawings. However, these terms are used as relative concepts and are described with reference to the directions indicated in the drawings.

[0059] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as those commonly understood by those of ordinary skill in the art to which the inventive concept belongs. 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 defined in this article.

[0060] The rechargeable battery according to an embodiment of the present invention is an ultra-compact battery, which may be a coin battery or a button battery. Here, the coin battery or button battery is a thin coin-type battery or a button-type battery, and refers to a battery having a height (H) to diameter (D) ratio (H / D) of 1 or less (see Figure 1 ).

[0061] In one embodiment, the coin cell or button cell is generally cylindrical and 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 to the flat top cross section).

[0062] However, the present invention is not limited to the coin cell or button cell as an example of the present invention, and the battery of the present invention may be a cylindrical battery or a pin-type battery. Herein, the case where the rechargeable battery according to an embodiment of the present invention is a coin cell or a button cell will be further described in detail as an example.

[0063] Figure 1 is a perspective view of a rechargeable battery according to an embodiment of the present invention; Figure 2 for Figure 1 An exploded perspective view of a rechargeable battery; Figure 3 For along Figure 1 A cross-sectional view taken along line III-III in FIG.

[0064] See also Figures 1 to 3 , a rechargeable battery 1 according to an embodiment includes an electrode assembly 10, a case 20, a cap assembly 30, and a housing 40. The cap assembly 30 includes a cap plate 31 and a terminal plate 33 combined together. As an example, the cap plate 31 and the terminal plate 33 are thermally fused by a thermally fused member 34 disposed therebetween.

[0065] The hot melt member 34 serves as a medium to connect the cap plate 31 and the terminal plate 33 to each other. For example, the hot melt member 34 may be formed of an electrically insulating material such as a polymer, and may be melted using a laser or the like to be fused to the cap plate 31 and the terminal plate 33.

[0066] In an embodiment, by coupling the terminal plate 33 to the cap plate 31 using the hot melt member 34 , a stable coupling structure can be formed while effectively insulating between the terminal plate 33 and the cap plate 31 without adding a separate insulating configuration.

[0067] Since the coin cell is manufactured in an ultra-compact size, it may have design limitations in terms of space, and accordingly, the function is ensured while simplifying its structure and manufacturing process. In this regard, in this embodiment, insulation and connection between the terminal plate 33 and the cap plate 31 are achieved by a hot melt member 34.

[0068] The electrode assembly 10 includes a first electrode 11 (e.g., a negative electrode) and a second electrode 12 (e.g., a positive electrode) provided on respective sides of a separator 13 as an electrical insulating material, and the electrode assembly 10 is formed by winding the first electrode 11, the separator 13, and the second electrode 12. Therefore, in one embodiment, the electrode assembly 10 may be formed in a jelly roll type. Although not shown separately, in one embodiment, the electrode assembly may be formed in a stacked type.

[0069] The electrode assembly 10 is configured for charging and discharging, and the winding axis of the electrode assembly 10 may be parallel to the height direction ( Figures 1 to 3 In one embodiment, the first end (the lower surface of the electrode assembly) 101 and the second end (the upper surface of the electrode assembly) 102 of the electrode assembly 10 may be flat and parallel to each other. In one embodiment, the electrode assembly 10 is not provided with a center pin, but a center pin (not shown) may be provided at the position of the winding axis.

[0070] The case 20 accommodates the electrode assembly 10 while facing the first end 101 of the electrode assembly 10. In one embodiment, the electrode assembly 10 is covered by the insulating sheet 14 and built in the case 20. As an example, the case 20 is formed as a cylinder accommodating the jelly roll type electrode assembly 10, and the cap assembly 30 seals the opening 21 of the cylindrical case 20.

[0071] In one embodiment, the electrode assembly 10 includes a first electrode tab 51 connected to the first electrode 11 and a second electrode tab 52 connected to the second electrode 12 , and the first electrode 11 and the second electrode 12 are led out to the first end 101 and the second end 102 , respectively.

[0072] In a state where the electrode assembly 10 is accommodated in the case 20 , the first electrode tab 51 is electrically connected to the bottom of the case 20 , and the second electrode tab 52 is electrically connected to the terminal plate 33 of the cap assembly 30 .

[0073] Furthermore, the cap plate 31 of the cap assembly 30 is coupled to the case 20 to cover the opening 21 while facing the second end 102 of the electrode assembly 10. In this way, the terminal plate 33 is coupled to the second electrode tab 52 while being coupled to the cap plate 31 with the hot melt member 34.

[0074] Here, a case where the first electrode 11 and the second electrode 12 are a negative electrode and a positive electrode, respectively, will be described as an example, but the present invention is not limited thereto, and the first electrode 11 and the second electrode 12 may be a positive electrode and a negative electrode, respectively.

[0075] In one embodiment, the first electrode (negative electrode) 11 is formed in a long extended strip shape and includes a negative electrode coating portion and a negative electrode uncoated portion, the negative electrode coating portion is a region where a current collector of a metal foil (e.g., a copper foil) is coated with a negative electrode active material layer, and the negative electrode uncoated portion is a region where an active material is not coated. The negative electrode uncoated portion may be disposed at an end portion in the length direction of the negative electrode.

[0076] In one embodiment, the second electrode (positive electrode) 12 is formed in a long extended strip shape and includes a positive electrode coated portion and a positive electrode uncoated portion, the positive electrode coated portion is a region where a current collector of a metal foil (e.g., an aluminum foil) is coated with a positive electrode active material layer, and the positive electrode uncoated portion is a region where an active material is not coated. The positive electrode uncoated portion may be disposed at an end portion in the length direction of the positive electrode.

[0077] The case 20 allows the electrode assembly 10 to be inserted into an opening 21 formed at one side of the case 20, and has a space for accommodating the electrode assembly 10 and the electrolyte therein. For example, the case 20 may be formed in a cylindrical shape having a height H smaller than its diameter D, and may have a circular opening 21 so that the cylindrical electrode assembly 10 corresponding to the internal space of the case 20 may be inserted.

[0078] In the cap assembly 30, the terminal plate 33 includes a flange portion 331 and a protruding terminal 332. The flange portion 331 is disposed between the cap plate 31 and the electrode assembly 10 to be electrically insulated from and attached to an inner surface of the cap plate 31.

[0079] The housing 40 is provided to prevent or substantially prevent reverse insertion when the rechargeable battery 1 is assembled into a kit. As an example, the housing 40 covers the cover plate 31 and is coupled to the case 20 to form an expansion portion P1 in the rechargeable battery 1. That is, the housing 40 forms a step on the side of the case 20 by the expansion portion P1.

[0080] Therefore, the housing 40 defines both sides of the height direction (up-down direction) of the rechargeable battery 1 as an expansion portion P1 on the upper side and a non-expansion portion P2 on the lower side. That is, in the rechargeable battery 1, the portion to which the housing 40 is coupled forms the expansion portion P1, and the portion without the housing 40 forms the non-expansion portion P2.

[0081] In the non-expanded portion P2, the case 20 has the negative electrode characteristics of the first electrode 11, and in the expanded portion P1, the terminal plate 33 has the positive electrode characteristics of the second electrode 12. In one embodiment, the cap plate 31 coupled to the case 20 has the negative electrode characteristics of the first electrode 11 together with the case 20. That is, the cap plate 31 and the case 20 are electrically connected to each other.

[0082] In the terminal plate 33, the protruding terminal 332 protrudes from the center of the flange portion 331 to the outside, passes through the terminal hole 311 of the cap plate 31, the through hole 341 of the hot melt member 34, and the through hole 411 of the housing 40, and the inner surface of the protruding terminal 332 is electrically connected to the second electrode tab 52. The second electrode tab 52 may be connected to the inner surface of the flange portion 331 or the inner surface of the protruding terminal 332, or may be connected to both.

[0083] The protruding terminal 332 protrudes more than the outer surface of the outer case 40 by a first height difference ΔH1 to form the outer surface of the rechargeable battery 1. That is, the outer surface of the protruding terminal 332 protrudes more than the outer surface of the cap plate 31 relative to the bottom of the case 20. Further, the outer surface of the protruding terminal 332 and the outer surface of the outer case 40 form a plane spaced apart from each other in the diameter direction while having the first height difference ΔH1.

[0084] In one embodiment, the housing 40 includes a plane portion 41 and a side portion 42. The plane portion 41 is configured to cover the outer surface of the cap plate 31 while exposing the protruding terminal 332 through the through hole 411. The side portion 42 extends along the side of the case 20 outside the plane portion 41 to cover a portion of the side of the case 20 and is coupled to the side of the case 20. In the rechargeable battery 1, the portion combined with the housing 40 forms an expansion portion P1, and the portion without the housing 40 forms a non-expansion portion P2.

[0085] Therefore, the housing 40 forms a step on the side of the shell 20 at the boundary between the expansion portion P1 and the non-expanded portion P2 in the height direction and the intersecting direction (diameter direction) orthogonal to the height direction. That is, the expansion portion P1 relatively increases in height or diameter compared to the non-expanded portion P2.

[0086] In the case 20, the outer shell 40 is not combined at the lower part, so that the outer diameter (i.e., the first diameter) of the case 20 is defined between the outer sides in the diameter direction of the case 20. The outer shell 40 is coupled to the upper part of the case 20 to define the outer diameter (i.e., the second diameter) of the case 40 between the outer sides in the diameter direction of the case 40. The outer diameter of the case 40 is greater than the outer diameter of the case 20. Therefore, there is a difference in diameter between the upper and lower parts of the rechargeable battery 1.

[0087] In one embodiment, the housing 40 may be formed of an electrically insulating material to prevent or substantially prevent an electrical short circuit between the outer surface of the protruding terminal 332 and the outer surface of the cap plate 31. For example, the housing 40 may include or be made of polypropylene (PP), polyethylene (PE), polyethylene terephthalate (PET), polyethylene naphthalate (PEN) resin or rubber. Although not shown, any synthetic resin or electrically insulating material may be applied to the housing.

[0088] In one embodiment, the through hole 411 of the housing 40 is concentric with the terminal hole 311 of the cover plate 31, and the inner diameter of the through hole 411 is formed to be larger than the outer diameter D11 of the protruding terminal 332. Therefore, the inner diameter D1 of the housing 20 is larger than the sum of the outer diameter D11 of the protruding terminal 332 and twice the diameter direction distance D12 of the flat surface portion 41 disposed on both sides of the protruding terminal 332 in the diameter direction (D1>D11+2×D12). Figure 3 As shown, the diameter direction distance D12 of the plane portion 41 refers to the distance measured along the diameter direction of the housing 40 from the inner side of the plane portion 41 to the portion of the plane portion 41 corresponding to the inner side wall of the housing 20. That is, there is a first gap G1 between the outer surface of the protruding terminal 332 and the inner wall of the through hole 411 of the housing 40.

[0089] When the side portion 42 of the housing 40 is coupled to the case 20 and the planar portion 41 is in close contact with the cap plate 31 , the first gap G1 prevents or substantially prevents the protruding terminal 332 from blocking an area around the through hole 411 .

[0090] In one embodiment, an insulating member 61 disposed at the outer periphery in the diameter direction of the hot melt member 34 is installed on the inner surface of the cap plate 31. The insulating member 61 may form an electrical insulation structure between the cap plate 31 and the second electrode tab 52 and between the cap plate 31 and the electrode assembly 10. As an example, the insulating member 61 has a through hole 611 corresponding to the outer diameter of the hot melt member 34.

[0091] In one embodiment, in the housing 40, the diameter direction distance D12 of the plane portion 41 may be greater than or equal to the height direction length H1 of the side portion 42 (D12 ≥ H1). Therefore, the height direction length H1 generates the fastening force of the housing 40 to the case 20, and the diameter direction distance D12 allows the insulation performance of the terminal plate 33 to be fully ensured.

[0092] In one embodiment, see Figure 1 In the rechargeable battery 1, the height H is defined as the distance between the outer plane of the housing 20 and the outer plane of the protruding terminal 332 in a state where the opening 21 of the housing 20 is closed and sealed by the cap assembly 30, and the battery diameter D is defined by the outer circumference of the outer shell 40. In one embodiment, the ratio of the height H to the battery diameter D is 1 or less (H / D≤1). Therefore, the rechargeable battery 1 of the present embodiment may be a coin-type battery or a button-type battery, and may be formed into a thin coin or button shape.

[0093] Here, another embodiment of the present invention is described. By comparing the first embodiment and the second embodiment, it is possible to omit the description of the same configuration and mainly describe the configuration different from the second embodiment.

[0094] Figure 4 is a perspective view of a rechargeable battery according to an embodiment of the present invention; Figure 5 for Figure 4 An exploded perspective view of a rechargeable battery; Figure 6 For along Figure 4 A cross-sectional view taken along line VI-VI in FIG.

[0095] See also Figures 4 to 6 In the rechargeable battery 2 according to an embodiment, the terminal plate 63 of the cap assembly 60 includes a flange portion 631 and a tab connection portion 632. The flange portion 631 is disposed on the outside of the cap plate 31 and is electrically insulated from and attached to the outer surface of the cap plate 31.

[0096] The housing 70 is provided to prevent or substantially prevent reverse insertion when assembling the rechargeable battery 2 into the kit. As an example, the housing 70 covers the cap plate 31 and is coupled to the housing 20 to form the expansion portion P3 in the rechargeable battery 2. On the cap plate 31, a portion of the outer surface is covered by the flange portion 631, and the flat surface (exposed surface 301) of the remaining portion of the outer surface is covered by the housing 70.

[0097] In the terminal plate 63, the tab connection portion 632 protrudes from the center of the flange portion 631 to the inside, and passes through the through hole 711 of the outer shell 70, the through hole 341 of the hot melt member 34 and the terminal hole 311 of the cover plate 31 to protrude toward the electrode assembly 10, and the second electrode tab 52 is electrically connected to the inner surface of the tab connection portion 632.

[0098] The flange portion 631 protrudes more than the outer surface of the housing 70 by the second height difference ΔH2 to form the outer surface of the rechargeable battery 2. In other words, the outer surface of the flange portion 631 protrudes more than the outer surface of the cap plate 31 relative to the bottom of the case 20. In addition, the outer surface of the flange portion 631 and the outer surface of the housing 70 form a plane that is spaced apart from each other in the diameter direction and has the second height difference ΔH2 at the same time.

[0099] For example, the housing 70 includes a plane portion 71 and a side portion 72. The plane portion 71 has a through hole 711 and is configured to cover the exposed surface 301 of the outer surface of the cap plate 31 while exposing the flange portion 631 of the terminal plate 63. The side portion 72 extends along the side of the case 20 outside the plane portion 71 to cover a portion of the side of the case 20 and is coupled to the side of the case 20. In the rechargeable battery 2, the portion where the housing 70 is combined with the case 20 forms an expansion portion P3, and the portion without the housing 70 forms a non-expansion portion P4.

[0100] The housing 70 covers the exposed surface 301 of the cover plate 31 and is coupled to the housing 20 to form the expansion portion P3. That is, the housing 70 forms a step on the side of the housing 20 through the expansion portion P3. That is, the expansion portion P3 relatively increases the height or diameter compared to the non-expansion portion P4.

[0101] In one embodiment, the through hole 711 of the housing 70 is concentric with the terminal hole 311 of the cover plate 31, and the inner diameter of the through hole 711 is formed to be larger than the outer diameter D21 of the flange portion 631. Therefore, the inner diameter D2 of the housing 20 is larger than the sum of the outer diameter D21 of the flange portion 631 and twice the diameter direction distance D22 of the flat surface portion 71 disposed on both sides of the flange portion 631 in the diameter direction (D2>D21+2×D22). Figure 6As shown, the diameter direction distance D22 of the plane portion 71 refers to the distance measured along the diameter direction of the housing 70 from the inner side of the plane portion 71 to the portion of the plane portion 71 corresponding to the inner side wall of the housing 20 .

[0102] That is, a second gap G2 exists between the outer surface of the flange portion 631 and the inner wall of the through hole 711 of the housing 70 .

[0103] The insulating member 62 disposed at the diameter-direction periphery of the tab connection portion 632 is mounted on the inner surface of the cap plate 31. The insulating member 62 may form an electrical insulation structure between the cap plate 31 and the second electrode tab 52 and between the cap plate 31 and the electrode assembly 10. As an example, the insulating member 62 has a through hole 621 corresponding to the terminal hole 311 of the cap plate 31. The through hole 621 allows the second electrode tab 52 to be connected to the inner surface of the tab connection portion 632. The through hole 621 is formed to have a smaller diameter than the terminal hole 311, thereby preventing or substantially preventing the second electrode tab 52 from contacting the cap plate 31.

[0104] In the housing 70, the diameter direction distance D22 of the plane portion 71 may be less than or equal to the height direction length H2 of the side portion 72 (D22 ≤ H2). Therefore, compared with the diameter direction distance D12 of the first embodiment, the diameter direction distance D22 is shorter, but the height direction length H2 allows the housing 70 to sufficiently ensure the fastening force of the shell 20.

[0105] While the present invention has been described in conjunction with what are presently considered to be some practical example embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but is intended to cover various modifications and equivalent arrangements included within the purview of the appended claims.

Claims

1. A rechargeable battery comprising: a case receiving an electrode assembly and including an opening in a height direction of the rechargeable battery, the electrode assembly including a first electrode, a second electrode, and a separator between the first electrode and the second electrode, and the case being connected to the first electrode through a first electrode tab; a cap assembly including a cap plate coupled to the housing and covering the opening and a terminal plate coupled to the cap plate, the terminal plate being connected to the second electrode through a second electrode tab; and a housing covering the cover plate and coupled to the housing, wherein an outer surface of the terminal plate protrudes further than an outer surface of the outer case to have a height difference in the height direction of the rechargeable battery, The cover is electrically connected to the housing, and The cap plate and the terminal plate are thermally fused with a heat-melting member therebetween and are electrically insulated from each other, and the heat-melting member does not overlap with the terminal hole of the cap plate in the height direction of the rechargeable battery.

2. The rechargeable battery according to claim 1, wherein The terminal board comprises: a flange portion, located between the cover plate and the electrode assembly and electrically insulated from and attached to an inner surface of the cover plate; and a protruding terminal protruding from the center of the flange portion to the outside, passing through the terminal hole of the cap plate and the through hole of the housing, and electrically connected to the second electrode tab through the inner surface of the terminal plate, and The protruding terminal protrudes more than the outer surface of the case by a first height difference to form an outer surface of the rechargeable battery.

3. The rechargeable battery of claim 2, wherein the housing comprises: A plane portion covering an outer surface of the cover plate; and The side portion extends along the side surface of the housing at the outer side of the planar portion to cover a portion of the side surface of the housing and is coupled to the side surface of the housing. The rechargeable battery of claim 3 , wherein the housing is formed of an electrically insulating material. 5 . The rechargeable battery of claim 4 , wherein the through hole of the case is concentric with the terminal hole of the cap plate, and an inner diameter of the through hole of the case is larger than an outer diameter of the protruding terminal. 6 . The rechargeable battery according to claim 3 , wherein an inner diameter of the case is larger than a sum of an outer diameter of the protruding terminal and twice a diameter direction distance of the planar portions provided on both sides in a diameter direction of the protruding terminal. 7 . The rechargeable battery according to claim 4 , wherein the outer case comprises PP, PE, PET, PEN resin or rubber.

8. The rechargeable battery according to claim 1, wherein the terminal plate comprises: a flange portion on an outer surface of the cover plate and electrically insulated from and attached to the outer surface of the cover plate; and a tab connection portion that protrudes from the center of the flange portion to the inside and protrudes toward the electrode assembly through the through hole of the housing and the terminal hole of the cover plate, and is electrically connected to the second electrode tab through the inner surface of the tab connection portion, and The flange portion protrudes more than the outer surface of the housing by a second height difference to form an outer surface of the rechargeable battery.

9. The rechargeable battery of claim 8, wherein the housing comprises: a plane portion including a through hole having an inner diameter greater than an outer diameter of the flange portion so as to cover an exposed surface of the cover plate while exposing the flange portion; and The side portion extends along the side surface of the housing at the outer side of the planar portion to cover a portion of the side surface of the housing and is coupled to the side surface of the housing. 10 . The rechargeable battery according to claim 9 , wherein an inner diameter of the case is larger than a sum of an outer diameter of the flange portion and twice a diameter direction distance of the planar portions provided on both sides of the flange portion in a diameter direction. 11 . The rechargeable battery according to claim 1 , wherein the outer case forms a step on a side surface of the case.

12. The rechargeable battery according to claim 1, wherein The housing defines a first diameter in a diametrical direction at a lower portion of the housing, and The housing is coupled to an upper portion of the case and defines a second diameter larger than the first diameter in a diameter direction.

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