Rechargeable battery

Abstract

A rechargeable battery includes: a case accommodating an electrode assembly and having an opening; a cap assembly including a cap plate coupled to the case to cover the opening and a terminal plate coupled to the cap plate; and a direction determining member covering the cap plate and coupled to the case to define a protruding portion.

Description

Technical Field

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

[0002] Unlike primary batteries, which cannot be charged, rechargeable batteries can be repeatedly charged and discharged. Low-capacity rechargeable batteries can be used in small electronic devices such as mobile phones, laptop computers, and camcorders, and large-capacity batteries have been widely used, for example, as a power source for driving electric motors of 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 secondary batteries have an operating voltage that is about three times higher than that of nickel-cadmium batteries or nickel-metal hydride batteries that can be used as power sources for portable electronic devices. Moreover, lithium-ion secondary batteries can also be widely used because of their high energy density per unit weight.

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

[0005] Ultra-small rechargeable batteries have the important tasks of providing the required capacity within a limited size, achieving an efficient structure while improving effective lightweighting, and enhancing 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, there is provided an ultra-small rechargeable battery. According to another aspect of an embodiment of the present invention, there is provided a rechargeable battery configured to prevent or substantially prevent reverse insertion.

[0008] According to another aspect of an embodiment of the present invention, there is provided a rechargeable battery configured to prevent or substantially prevent an external short circuit of portions having different polarities in a cap assembly.

[0009] A rechargeable battery according to one or more embodiments of the present invention includes: a case accommodating an electrode assembly and having an opening; a cover assembly including a cover plate coupled to the case to cover the opening and a terminal plate coupled to the cover plate; and a direction determining member covering the cover plate and coupled to the case to define a protruding portion.

[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 by a first electrode tab, and the terminal plate may be connected to the second electrode by 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 and electrically insulated from each other by a thermal fusion member between the cap plate and the terminal plate.

[0012] The terminal plate may include: a flange portion, which is 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 outward from the flange portion to be inserted into the terminal hole of the cover plate and is electrically connected to the second electrode terminal tab via the inner surface of the terminal plate.

[0013] Outer surfaces of the protruding terminals and an outer surface of the cap plate may respectively define plane surfaces at the same height based on the bottom of the case and be spaced apart from each other.

[0014] The direction determining member may include: a planar portion including through holes corresponding to the protruding terminals to cover the outer surface of the cover plate while exposing the protruding terminals; and a side portion extending from the outer surface of the planar portion along the side of the housing to cover and be connected to a portion of the side of the housing.

[0015] The direction determining member may include an electrically insulating material to electrically insulate outer surfaces of the protruding terminals from an outer surface of the cap plate.

[0016] The through hole of the direction determining member may be concentric with the terminal hole of the cap plate, and a diameter of the through hole may be smaller than a diameter of the terminal hole, thereby covering the entire outer surface panel of the cap plate at one side of the protruding terminal.

[0017] The direction determining member may include polypropylene (PP), polyethylene (PE), polyethylene terephthalate (PET), polyethylene naphthalate (PEN) resin, or rubber.

[0018] The diameter direction length D1 of the planar portion may be equal to or greater than the height direction length H1 of the side portion (D1 ≥ H1).

[0019] The terminal plate may include: a flange portion, which is on the outside of the cover plate and is electrically insulated from and attached to the outer surface of the cover plate; and a tab connecting portion, which protrudes inward from the flange portion to be inserted into the terminal hole of the cover plate and is electrically connected to the second electrode tab via the inner surface of the terminal plate.

[0020] Based on the bottom of the housing, the outer surface of the cover plate may be partially covered by the flange, and the remaining exposed surface is defined as a plane surface.

[0021] The direction determining member may include: a planar portion including a through hole corresponding to the flange portion to cover the exposed surface of the cover plate while exposing the flange portion; and a side portion extending from an outer surface of the planar portion along a side surface of the shell to cover and connect to a portion of the side surface of the shell.

[0022] The height of the plane portion may be equal to or smaller than the height of the flange portion based on the bottom of the housing.

[0023] The diameter direction length D2 of the planar portion may be equal to or smaller than the height direction length H2 of the side portion (D2 ≤ H2).

[0024] The rechargeable battery according to one or more embodiments of the present invention may further include an insulating member on an outer circumference of the tab connection part and mounted to an inner surface of the cap plate.

[0025] The direction determining member may define a step on the side surface of the housing by the protruding portion.

[0026] The housing may define a first diameter in an outer surface in a diametrical direction at a lower portion, and the direction determining member may be coupled to an upper portion of the housing to define a second diameter greater than the first diameter in the diametrical direction.

[0027] In a rechargeable battery according to one or more embodiments of the present invention, since the direction determining member covers the cover plate and is coupled to the housing, a protruding portion may be formed. The protruding portion forms a step on the side of the housing. That is, since the direction determining member protrudes more than the side of the housing at the cover plate and its adjacent side, the step may be formed with a protruding portion having an increased height or diameter. Therefore, visually or structurally, reverse insertion of the rechargeable battery may be effectively prevented.

[0028] In a rechargeable battery according to one or more embodiments, two parts of a cap assembly having different polarities (e.g., a cap plate and a terminal plate) are exposed in the same direction, and a direction determining member may cover at least one of the two parts having different polarities. When the direction determining member is formed of an electrically insulating material, the two parts may be effectively prevented from being short-circuited by conductive foreign matter.

[0029] In the rechargeable battery of one or more embodiments, the protruding portion is formed by the direction determining member coupled to the case, and the protruding portion can buffer physical impact, thereby improving safety, for example, in a drop test and a tumble test. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 is a perspective view showing a rechargeable battery according to an embodiment of the present invention.

[0031] Figure 2 yes Figure 1An exploded perspective view of a rechargeable battery.

[0032] Figure 3 is along Figure 1 A cross-sectional view taken along line III-III.

[0033] Figure 4 is a perspective view showing a rechargeable battery according to another embodiment of the present invention.

[0034] Figure 5 yes Figure 4 An exploded perspective view of a rechargeable battery.

[0035] Figure 6 is along Figure 4 A cross-sectional view taken along line VI-VI.

[0036] Description of Reference Numerals

[0037] 1, 2: Rechargeable battery 10: Electrode assembly

[0038] 11: First electrode 12: Second electrode

[0039] 13: Partition 14: Insulation sheet

[0040] 20: Shell 21: Opening

[0041] 30, 60: Cover assembly 31: Cover plate

[0042] 33, 63: Terminal plate 34: Thermal fusion component

[0043] 40, 70: Direction determining member 41, 71: Plane portion

[0044] 42, 72: Side 51: First electrode terminal piece

[0045] 52: second electrode tab 61, 62: insulating member

[0046] 101: first end 102: second end

[0047] 301: Exposed surface 311: Terminal hole

[0048] 331, 631: flange part 332: protruding terminal

[0049] 341: Through hole 411, 711: Through hole

[0050] 611, 621: Through hole 632: Lug connection part

[0051] D: battery diameter D1, D2: length in diameter direction

[0052] D3: First diameter H: Height

[0053] H1, H2: Length in height direction P1, P3: Protruding part

[0054] P2, P4: Non-extended part ΔH: Height difference DETAILED DESCRIPTION

[0055] The present invention will be more fully described herein with reference to the accompanying drawings, in which some example 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 considered illustrative rather than restrictive in nature. In the specification, the same reference numerals represent the same elements throughout.

[0056] Furthermore, in this 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. On the other hand, in this specification, it should be understood that when a component is referred to as being "directly connected or coupled" to another component, it may be connected or coupled to the other component without interposing another component therebetween.

[0057] It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the present invention.

[0058] Unless the context clearly indicates otherwise, singular forms shall include plural forms.

[0059] It will be further understood that terms such as “comprises,” “includes,” or “has” used in this specification specify the presence of stated features, numbers, steps, operations, components, parts, or a combination thereof, but do not preclude the presence or addition of one or more other features, numbers, steps, operations, components, parts, or a combination thereof.

[0060] 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, without departing from the scope of the exemplary embodiments of the present invention, a first element may be referred to as a "second" element, and similarly, a second element may be referred to as a "first" element. Unless the context clearly indicates otherwise, a term in the singular may include a plural form.

[0061] 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.

[0062] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by a person 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 that in the context of the relevant technology and are clearly defined herein unless they are interpreted in an ideal or overly formal sense.

[0063] The rechargeable battery according to an embodiment of the present invention as an ultra-compact battery 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 ratio (H / D) of height (H) to diameter (D) of 1 or less (see Figure 1 ).

[0064] In one embodiment, the coin cell or button cell is 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 set to the maximum distance of the outer periphery of the housing (or direction determining member) based on the horizontal direction of the battery, and the height is set to the minimum distance between the housing of the battery and the outer plane of the cover plate (or direction determining member).

[0065] However, the present invention is not limited to the coin cell or button cell provided as an example of the present invention, and the battery of the present invention may be a cylindrical or pin-type battery. Here, the case where the rechargeable battery according to an embodiment of the present invention is a coin cell or button cell will be described in more detail.

[0066] Figure 1 is a perspective view showing a rechargeable battery according to an embodiment of the present invention; Figure 2 yes Figure 1 an exploded perspective view of a rechargeable battery; and Figure 3 is along Figure 1 A cross-sectional view taken along line III-III.

[0067] Reference 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 direction determining member 40. The cap assembly 30 includes a cap plate 31 and a terminal plate 33 coupled to each other. As an example, the cap plate 31 and the terminal plate 33 are thermally fused by a thermal fusion member 34 disposed between the cap plate 31 and the terminal plate 33.

[0068] In one embodiment, the heat fusion member 34 serves as a medium to interconnect the cap plate 31 and the terminal plate 33. For example, the heat fusion 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 fuse to the cap plate 31 and the terminal plate 33.

[0069] In one embodiment, by coupling the terminal plate 33 to the cap plate 31 using the thermal fusion member 34 , a stable coupling structure may be formed while effectively insulating the terminal plate 33 from the cap plate 31 without adding a separate insulating structure.

[0070] Since the coin cell is manufactured in an ultra-compact size, it may have design limitations in terms of space, and thus, it is desired to ensure functionality while simplifying the structure and its manufacturing process. In this regard, in one embodiment, the insulation and coupling between the terminal plate 33 and the cap plate 31 can be achieved by a thermal fusion member 34.

[0071] In one embodiment, 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 may be formed by winding the first electrode 11, the separator 13, and the second electrode 12. Therefore, the electrode assembly 10 may be formed in a jelly roll type. In another embodiment, although not shown separately, the electrode assembly may be formed in a stacked type.

[0072] The electrode assembly 10 is configured for charging and discharging current, and the winding axis in the electrode assembly 10 may be parallel to the height direction ( Figure 1-Figure 3 In one embodiment, the first end (the lower surface or cross section of the electrode assembly) 101 and the second end (the upper surface or cross section of the electrode assembly) 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.

[0073] 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 accommodated in the case 20. As an example, the case 20 is formed as a cylinder accommodating the electrode assembly 10 of a jelly roll type, and the cap assembly 30 seals the opening 21 of the cylindrical case 20.

[0074] 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.

[0075] In a state in which 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 .

[0076] In addition, the cap plate 31 of the cap assembly 30 is coupled to the case 20 while facing the second end 102 of the electrode assembly 10 to cover the opening 21. The terminal plate 33 is coupled to the second electrode tab 52 while being coupled to the cap plate 31 through the thermal fusion member 34.

[0077] 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.

[0078] The first electrode 11 is formed in a long strip shape and includes: a negative electrode coating portion, which is a region where a negative electrode active material layer is coated to a current collector of a metal foil (e.g., Cu foil); and a negative electrode uncoated portion, which is a region where an active material is not coated. The negative electrode uncoated portion may be provided at an end portion in a length direction of the negative electrode.

[0079] The second electrode 12 is formed in a long strip shape and includes: a positive electrode coating portion, which is a region where a positive electrode active material layer is coated on a current collector of a metal foil (e.g., Al foil); and a positive electrode uncoated portion, which is a region where an active material is not coated. The positive electrode uncoated portion may be provided at an end portion in the length direction of the positive electrode.

[0080] The case 20 allows the electrode assembly 10 to be inserted into an opening 21 formed in a side thereof, and has a space for accommodating the electrode assembly 10 and an electrolyte therein. In one embodiment, for example, the case 20 is formed in a cylindrical shape having a height lower than its diameter, and has a circular opening 21 so that the cylindrical electrode assembly 10 corresponding to its internal space can be inserted therein.

[0081] 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.

[0082] The protruding terminal 332 protrudes outward from the flange portion 331 and is inserted into the through hole 341 of the heat fusion member 34 and the terminal hole 311 of the cap plate 31, 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 the inner surface of the flange portion 331 and the inner surface of the protruding terminal 332.

[0083] In one embodiment, the outer surface of the protruding terminal 332 and the outer surface of the cap plate 31 form a plane at the same height based on the bottom of the case 20 and are spaced apart from each other in the diameter direction. When the rechargeable battery 1 including this structure is assembled into a kit, in order to prevent or substantially prevent reverse insertion, the rechargeable battery 1 according to one embodiment further includes a direction determining member 40.

[0084] The direction determining member 40 covers the cover plate 31 and is coupled to the housing 20 to form a protruding portion P1. That is, the direction determining member 40 forms a step on the side of the housing 20 through the protruding portion P1.

[0085] Therefore, the direction determining member 40 can define both sides of the height direction of the rechargeable battery 1 as a protruding portion P1 on the upper side and a non-protruding portion P2 on the lower side. That is, in the rechargeable battery 1, the portion coupled with the direction determining member 40 forms the protruding portion P1, and the portion without the direction determining member 40 forms the non-protruding portion P2.

[0086] In the non-extending portion P2, the case 20 and the bottom of the rechargeable battery 1 have the negative polarity of the first electrode 11, and in the extending portion P1, the terminal plate 33 has the positive polarity of the second electrode 12. In one embodiment, the cap plate 31 coupled to the case 20 has the negative polarity 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.

[0087] In one embodiment, for example, the direction determining member 40 includes a plane portion 41 and a side portion 42. The plane portion 41 includes a through hole 411 corresponding to the protruding terminal 332 to cover the outer surface of the cap plate 31 while exposing the protruding terminal 332. The side portion 42 extends from the outer surface of the plane portion 41 along the side of the housing 20, thereby being coupled to the side of the housing 20 by receiving a portion of the side of the housing 20. In the rechargeable battery 1, the portion coupled to the direction determining member 40 forms a protruding portion P1, and the portion without the direction determining member 40 forms a non-protruding portion P2.

[0088] Therefore, the direction determining member 40 forms a step on the side of the housing 20 at the boundary between the protruding portion P1 and the non-protruding portion P2 in the height direction and the intersecting direction (diameter direction) orthogonal to the height direction. That is, the protruding portion P1 relatively increases the height or diameter compared to the non-protruding portion P2.

[0089] In one embodiment, for the housing 20, the direction determining member 40 is not coupled at the bottom, so that the first diameter D3 is defined between the outer sides of the housing 20 in the diameter direction. The direction determining member 40 is coupled to the upper portion of the housing 20 and defines a second diameter (the same as the diameter D of the battery) between the outer sides of the direction determining member 40 in the diameter direction. The second diameter D is greater than the first diameter D3. Therefore, there is a diameter difference between the upper and lower portions of the rechargeable battery 1.

[0090] In one embodiment, the direction determining member 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 direction determining member 40 may be formed of polypropylene (PP), polyethylene (PE), polyethylene terephthalate (PET), polyethylene naphthalate (PEN) resin, or rubber. Although not shown, a synthetic resin or an electrically insulating material may be applied to the direction determining member 40.

[0091] In one embodiment, the through hole 411 of the direction determining member 40 is concentric with the terminal hole 311 of the cover plate 31, and the diameter of the through hole 411 is smaller than the diameter of the terminal hole 311, so that the direction determining member 40 completely covers the outer surface of the cover plate 31 from the side of the protruding terminal 332, thereby effectively preventing external short circuit caused by conductive materials.

[0092] In one embodiment, an insulating member 61 disposed on the outer circumference in the diameter direction of the heat fusion member 34 is mounted 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. In one embodiment, the insulating member 61 includes a through hole 611 corresponding to the outer diameter of the heat fusion member 34.

[0093] In the direction determining member 40, the diameter direction length D1 of the plane portion 41 may be equal to or greater than the height direction length H1 (D1 ≥ H1) of the side portion 42. Therefore, the height direction length H1 forms the clamping force of the direction determining member 40 to the housing 20, and the diameter direction length D1 enables the insulation performance of the terminal plate 31 to be fully ensured.

[0094] In one embodiment, reference Figure 1 In the rechargeable battery 1, in a state where the opening 21 of the housing 20 is closed and sealed by the cap assembly 30, the height H is defined as the distance between the housing 20 and the outer plane of the direction determining member 40, and the diameter D of the battery 20 is defined as the outer circumference of the direction determining member 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 one embodiment is a coin-type battery or a button-type battery, and can be formed into a thin coin or button shape.

[0095] Here, another embodiment of the present invention will be described. Further description of the same configuration as above may be omitted, and Figures 4 to 6 The illustrated embodiments describe different configurations.

[0096] Figure 4 is a perspective view showing a rechargeable battery according to another embodiment of the present invention; Figure 5 yes Figure 4 an exploded perspective view of a rechargeable battery; and Figure 6 It is along Figure 4 A cross-sectional view taken along line VI-VI.

[0097] Reference Figures 4 to 6 In a rechargeable battery 2 according to another embodiment, in the cap assembly 60, the terminal plate 63 includes a flange portion 631 and a tab connection portion 632. The flange portion 631 is provided on the outer side of the cap plate 31, and is electrically insulated from and attached to the outer surface of the cap plate 31.

[0098] The tab connection part 632 protrudes inward from the flange portion 631 and is inserted into the through hole 341 of the thermal fusion member 34 and the terminal hole 311 of the cap plate 31 , and the second electrode tab 52 is electrically connected to the inner surface of the tab connection part 632 .

[0099] Based on the bottom of the housing 20, a portion of the outer surface of the cover plate 31 is covered by the flange portion 631, and the remaining portion of the outer surface remaining on the outer surface (exposed surface 301) can be formed as a flat surface (plane surface). In order to prevent or substantially prevent the reverse insertion of the rechargeable battery 2 including this structure, the rechargeable battery 2 according to an embodiment includes a direction determining member 70.

[0100] For example, the direction determining member 70 includes a plane portion 71 and a side portion 72. The plane portion 71 includes a through hole 711 corresponding to the flange portion 631 to cover the exposed surface 301 of the outer surface of the cap plate 31 while exposing the flange portion 63 of the terminal plate 63. The side portion 72 extends from the outer surface of the plane portion 71 along the side of the housing 20 to cover a portion of the side of the housing 20 and is coupled to the side of the housing 20. In the rechargeable battery 2, the portion coupled to the direction determining member 70 defines a protruding portion P3, and the portion without the direction determining member 70 defines a non-protruding portion P4.

[0101] Therefore, the direction determining member 70 covers the exposed surface 301 of the cover plate 31 and is coupled to the housing 20 to form a protruding portion P3. That is, the direction determining member 70 forms a step on the side of the housing 20 through the protruding portion P3. That is, the protruding portion P3 relatively increases the height or diameter compared to the non-protruding portion P4.

[0102] The height of the plane portion 71 is the height of the flange portion 631 or less based on the bottom of the housing 20. Therefore, the plane portion 71 and the flange portion 631 may have a height difference ΔH. The height difference ΔH makes it possible to more effectively prevent reverse insertion of the rechargeable battery 2 and to more effectively prevent external short circuits between the flange portion 631 of the terminal plate 63 and the housing 20.

[0103] In the direction determining member 70, the diameter direction length D2 of the plane portion 71 may be equal to or less than the height direction length H2 (D2 ≤ H2) of the side portion 72. Therefore, although the diameter direction length D2 may be short, the height direction length H2 may ensure sufficient fastening force of the direction determining member 70 to the housing 20.

[0104] In one embodiment, the insulating member 62 disposed on the outer circumference of the tab connection part 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.

[0105] The insulating member 62 includes 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. In one embodiment, the through hole 621 has a diameter smaller than that of the terminal hole 311 to prevent or substantially prevent the second electrode tab 52 from contacting the cap plate 31.

[0106] While the invention has been described in conjunction with what are presently considered to be some possible exemplary 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 housing accommodating the electrode assembly and having an opening; a cover assembly including a cover plate coupled to the housing to cover the opening and a terminal plate coupled to the cover plate, the cover plate and the terminal plate having different polarities; and a direction determining member covering the cover plate and directly coupled to the housing to define a protruding portion, the direction determining member comprising an electrically insulating material, The direction determining member defines a step on a side surface of the housing through the protruding portion.

2. The rechargeable battery according to claim 1, wherein The electrode assembly includes a first electrode, a second electrode, and a separator between the first electrode and the second electrode, The housing is connected to the first electrode via a first electrode tab, and The terminal plate is connected to the second electrode via the second electrode tab.

3. The rechargeable battery according to claim 2, wherein The cover plate is electrically connected to the housing, and The cap plate and the terminal plate are heat-fused by a heat-fusion member between the cap plate and the terminal plate and are electrically insulated from each other.

4. The rechargeable battery according to claim 2, wherein the terminal plate comprises: a flange portion between the cap plate and the electrode assembly and electrically insulated from and attached to an inner surface of the cap plate; and A protruding terminal protrudes outward from the flange portion to be inserted into the terminal hole of the cap plate and electrically connected to the second electrode tab via an inner surface of the terminal plate. 5 . The rechargeable battery of claim 4 , wherein an outer surface of the protruding terminal and an outer surface of the cap plate define a plane surface at the same height based on the bottom of the case and are spaced apart from each other.

6. The rechargeable battery according to claim 5, wherein the direction determining member comprises: a plane portion including through holes corresponding to the protruding terminals to cover the outer surface of the cover plate while exposing the protruding terminals; and The side portion extends from an outer surface of the planar portion along a side surface of the housing to cover and be coupled to a portion of the side surface of the housing. 7 . The rechargeable battery of claim 6 , wherein the direction determining member electrically insulates an outer surface of the protruding terminal from an outer surface of the cap plate.

8. The rechargeable battery according to claim 7, wherein The through hole of the direction determining member is concentric with the terminal hole of the cover plate, and The through hole has a diameter smaller than a diameter of the terminal hole, thereby covering the entire outer surface of the cap plate at one side of the protruding terminal. 9 . The rechargeable battery of claim 7 , wherein the direction determining member comprises polypropylene, polyethylene, polyethylene terephthalate, polyethylene naphthalate resin, or rubber. 10 . The rechargeable battery according to claim 6 , wherein a length in a diameter direction of the planar portion is equal to or greater than a length in a height direction of the side portion.

11. The rechargeable battery according to claim 2, wherein the terminal plate comprises: a flange portion, outside the cover plate, electrically insulated from and attached to an outer surface of the cover plate; and A tab connection portion protrudes inward from the flange portion to be inserted into the terminal hole of the cap plate and electrically connected to the second electrode tab via an inner surface of the terminal plate. 12 . The rechargeable battery of claim 11 , wherein an outer surface of the cap plate is partially covered by the flange based on a bottom of the case, and a remaining exposed surface of the cap plate defines a planar surface.

13. The rechargeable battery according to claim 12, wherein the direction determining member comprises: a plane portion including a through hole corresponding to the flange portion to cover the exposed surface of the cover plate while exposing the flange portion; and A side portion extends from an outer surface of the planar portion along a side surface of the housing to cover and be coupled to a portion of the side surface of the housing. 14 . The rechargeable battery according to claim 13 , wherein a height of the plane portion is equal to or smaller than a height of the flange portion based on a bottom of the case. 15 . The rechargeable battery according to claim 13 , wherein a length in a diameter direction of the planar portion is equal to or smaller than a length in a height direction of the side portion. 16 . The rechargeable battery of claim 13 , further comprising an insulating member on an outer circumference of the tab connection part and arranged at an inner surface of the cap plate.

17. The rechargeable battery according to claim 1, wherein The housing defines a first diameter at the outer surface in a diametrical direction at a lower portion, and The direction determining member is coupled to an upper portion of the housing to define a second diameter greater than the first diameter in the diameter direction.

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