Patent Publication Number: US-2022231362-A1

Title: Rechargeable battery

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims priority to and the benefit of Korean Patent Application No. 10-2021-0007544, filed in the Korean Intellectual Property Office on Jan. 19, 2021, the entire content of which is incorporated herein by reference. 
     BACKGROUND 
     1. Field 
     Aspects of embodiments of the present disclosure relate to a rechargeable battery. 
     2. Description of the Related Art 
     In general, a rechargeable battery is a battery that is designed to be charged and discharged. 
     Recently, as the demand for wearable devices, such as headphones, earphones, smartwatches, and body-attached medical devices using wireless communication, such as Bluetooth, increases, the demand for an ultra-small rechargeable battery mounted on (or in) the wearable device is increasing. 
     Such an ultra-small rechargeable battery includes a case accommodating an electrode assembly including both electrodes, the case being connected to one electrode of the electrode assembly, and a terminal portion connected with the other electrode of the electrode assembly while sealing the case and the electrode assembly. 
     However, a conventional ultra-small rechargeable battery uses a polymer material to close and seal and insulate between the terminal portion and the case, and thus, it is vulnerable to high temperature and high humidity environments. 
     The above information disclosed in this Background section is for enhancement of understanding of the background of the present disclosure, and therefore, it may contain information that does not form the prior art that is already known to a person of ordinary skill in the art. 
     SUMMARY 
     An embodiment of the present disclosure provides a rechargeable battery that is strong (e.g., resilient or durable) in a high temperature and high humidity environment. 
     According to an embodiment of the present disclosure, a rechargeable battery includes: an electrode assembly including a first electrode, a second electrode, and a separator between the first electrode and the second electrode; a case accommodating the electrode assembly and connected to the first electrode, the case having an opening exposing the electrode assembly; a cap plate coupled with the case and covering an outer region of the opening in the case, the cap plate having an opening exposing a central region of the opening in the cap plate and including an insulation layer coated on a surface thereof corresponding to the opening in the cap plate; and a terminal portion connected with the second electrode and bonded in an insulated manner to the cap plate. The terminal portion covers the opening in the cap plate, and the terminal portion includes a plating layer that is directly bonded to the insulation layer of the cap plate. 
     The terminal portion may further include a first terminal portion including a flange portion covering the opening in the cap plate and being on the cap plate and a protruding portion that extends from the flange portion into the opening in the cap plate, and the plating layer may be coated on a surface of the first terminal portion. 
     The plating layer may close and seal between the first terminal portion and the cap plate. 
     The terminal portion may further include a second terminal portion in the opening in the cap plate, and the plating layer may be coated on a surface of the second terminal portion. 
     The plating layer may close and seal between the second terminal portion and the cap plate. 
     The plating layer may completely fill the opening in the cap plate. 
     The plating layer may include: a first plating portion filling the opening in the cap plate; a second plating portion extend from the first plating portion and covering an upper surface of the cap plate; and a third plating portion extending from the first plating portion and covering a lower surface of the cap plate. 
     The insulation layer may include: a first coating layer coated on a side surface of the cap plate that forms the opening in the cap plate; a second coating layer coated on an upper surface of the cap plate around the opening in the cap plate; and a third coating layer coated on a lower surface of the cap plate around the opening in the cap plate. 
     The first coating layer, the second coating layer, and the third coating layer may be integrally formed. 
     The second coating layer may be coated on only a part of the upper surface of the cap plate, and the third coating layer may be coated on only a part of the lower surface of the cap plate. 
     The plating layer may directly contact the first coating layer, the second coating layer, and the third coating layer. 
     The first coating layer may be completely covered by the plating layer, and a part of the second coating layer and a part of the third coating layer may not overlap the plating layer. 
     The insulation layer may include a ceramic material. 
     The electrode assembly may further include: a first electrode tab extended from the first electrode and welded to the case; and a second electrode tab extended from the second electrode and welded to the terminal portion. 
     The case and the cap plate may have the same polarity as the first electrode, and the terminal portion may have the same polarity as the second electrode. 
     The rechargeable battery may be a coin cell or a button cell. 
     A ratio of a height to a diameter of the coin cell or the button cell may be 1 or less. 
     According to embodiments of the present disclosure, a rechargeable battery that is strong to (e.g., durable or resilient in a) high temperature and high humidity environments is provided. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a rechargeable battery according to an embodiment. 
         FIG. 2  is a cross-sectional view taken along the line II-II in  FIG. 1 . 
         FIG. 3  is an enlarged view of the portion A of  FIG. 2 . 
         FIG. 4  is a cross-sectional view of a rechargeable battery according to another embodiment. 
         FIG. 5  is an enlarged view of the portion B of  FIG. 4 . 
         FIG. 6  is a cross-sectional view of a rechargeable battery according to another embodiment. 
         FIG. 7  is an enlarged view of the portion C of  FIG. 6 . 
     
    
    
     DETAILED DESCRIPTION 
     The present disclosure will be described more fully hereinafter with reference to the accompanying drawings, in which embodiments of the present disclosure are shown. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present disclosure. 
     The terminology used herein is for the purpose of describing particular example embodiments of the present disclosure and is not intended to be limiting of the described example embodiments of the present disclosure. As used herein, the singular forms “a” and “an” are intended to include the plural forms as well, unless the context clearly indicates otherwise. In addition, unless explicitly described to the contrary, the words “have,” “include,” and “comprise”, and variations such as “has,” “having,” “includes,” “including,” “comprises,” or “comprising”, will be understood to imply the inclusion of stated elements but not the exclusion of any other elements. 
     It will be understood that when an element or layer is referred to as being “on,” “connected to,” or “coupled to” another element or layer, it may be directly on, connected, or coupled to the other element or layer or one or more intervening elements or layers may also be present. When an element or layer is referred to as being “directly on,” “directly connected to,” or “directly coupled to” another element or layer, there are no intervening elements or layers present. For example, when a first element is described as being “coupled” or “connected” to a second element, the first element may be directly coupled or connected to the second element or the first element may be indirectly coupled or connected to the second element via one or more intervening elements. 
     In the figures, dimensions of the various elements, layers, etc. may be exaggerated for clarity of illustration. The same reference numerals designate the same elements. Further, the use of “may” when describing embodiments of the present disclosure relates to “one or more embodiments of the present disclosure.” Expressions, such as “at least one of,” when preceding a list of elements, modify the entire list of elements and do not modify the individual elements of the list. As used herein, the terms “use,” “using,” and “used” may be considered synonymous with the terms “utilize,” “utilizing,” and “utilized,” respectively. As used herein, the terms “substantially,” “about,” and similar terms are used as terms of approximation and not as terms of degree, and are intended to account for the inherent variations in measured or calculated values that would be recognized by those of ordinary skill in the art. 
     Spatially relative terms, such as “beneath,” “below,” “lower,” “above,” “upper,” and the like, may be used herein for ease of description to describe one element or feature&#39;s relationship to another element(s) or feature(s) as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as “below” or “beneath” other elements or features would then be oriented “above” or “over” the other elements or features. Thus, the term “below” may encompass both an orientation of above and below. The device may be otherwise oriented (rotated 90 degrees or at other orientations), and the spatially relative descriptors used herein should be interpreted accordingly. 
     Hereinafter, referring to  FIG. 1  to  FIG. 3 , a rechargeable battery according to an embodiment will be described. 
     A rechargeable battery according to an embodiment is an ultra-small rechargeable battery and may be a coin-type battery (e.g., a coin cell) or a button-type battery (e.g., a button cell) but is not limited thereto. In some embodiments, the rechargeable battery may be a cylindrical or pin-type battery. 
     Here, the coin-type battery or the button-type battery is a thin coin or button-type battery and may imply a battery of which a ratio (e.g., a height/diameter ratio) of a height to a diameter is 1 or less, but this is not restrictive. Because the coin-type battery or the button-type battery is generally (or primarily) cylindrical, the cross-section in the horizontal direction is circular, but the present disclosure is not limited thereto. In some embodiments, the rechargeable battery may have an elliptical or polygonal shape in the horizontal direction. The diameter may be a maximum distance with reference to the horizontal direction of the battery, and the height may be a maximum distance (e.g., a distance from a flat top surface to a flat bottom surface in a cross-section) with the vertical direction of the battery as a reference. 
       FIG. 1  is a perspective view of a rechargeable battery according to an embodiment, and  FIG. 2  is a cross-sectional view taken along the line II-II in  FIG. 1 . 
     Referring to  FIG. 1  and  FIG. 2 , a rechargeable battery  1000  according to an embodiment includes an electrode assembly  100 , a case  200 , a cap plate  300 , and a terminal portion  400 . 
     The electrode assembly  100  is accommodated in the case  200 . A lower portion of the electrode assembly  100  faces a bottom portion of the case  200 , and an upper portion of the electrode assembly  100  faces the cap plate  300  and the terminal portion  400  covering an opening  210  of the case  200 . The upper and lower portions of the electrode assembly  100  may have a planar shape parallel to each other, but the present disclosure is not limited thereto. 
     The electrode assembly  100  includes a first electrode  110 , a second electrode  120 , a separator  130 , a first electrode tab  140 , and a second electrode tab  150 . 
     The first electrode  110  and the second electrode  120  are spaced apart from each other, and a separator  130  including an insulating material is positioned between the first electrode  110  and the second electrode  120 . The first electrode  110  may be an anode, and the second electrode  120  may be a cathode, but they are not limited thereto. In some embodiments, the first electrode  110  may be a cathode, and the second electrode  120  may be an anode. 
     The first electrode  110  has a band shape extending in one direction and includes an anode coated region, where an anode active material layer is applied to a current collector of a metal foil (e.g., a Cu foil), and an anode uncoated region, where no active material is applied. The anode uncoated region may be positioned at one end in the extension direction of the first electrode  110 . 
     The second electrode  120  has a band shape extending in one direction while being spaced apart from the first electrode  110  with the separator  130  therebetween and includes a cathode coated region, where a cathode active material layer is applied to a current collector of a metal foil (e.g., an Al foil) and a cathode uncoated region, where no active material is applied. 
     The cathode uncoated region may be located at one end in the extending direction of the second electrode  120 . 
     The separator  130  extends in one direction between the first electrode  110  and the second electrode  120  to prevent a short circuit between the first electrode  110  and the second electrode  120 . 
     The first electrode  110 , the separator  130 , and the second electrode  120  are sequentially stacked and wound in the form of a jelly roll. The present disclosure is not limited thereto, and the first electrode  110 , the separator  130 , and the second electrode  120  may be formed in various known shapes. Each of the first electrode  110 , the second electrode  120 , and the separator  130  may include various known materials. 
     The first electrode tab  140  extends from the first electrode  110  of the electrode assembly  100  to the case  200 . The first electrode tab  140  is coupled to the bottom portion of the case  200  to connect the first electrode  110  and the case  200  to each other. The first electrode tab  140  contacts the first electrode  110  and the case  200 . The first electrode tab  140  is welded to the bottom portion of the case  200 , but the present disclosure is not limited thereto. The case  200  has the same polarity as the first electrode  110  via the first electrode tab  140 . 
     The second electrode tab  150  extends from the second electrode  120  of the electrode assembly  100  to the terminal portion  400 . The second electrode tab  150  is coupled to a plating layer  410  of the terminal portion  400  to connect the second electrode  120  and the terminal portion  400  to each other. The second electrode tab  150  contacts the second electrode  120  and the terminal portion  400 . The second electrode tab  150  is welded to the surface of the plating layer  410  of the terminal portion  400 , but the present disclosure is not limited thereto. The terminal portion  400  has the same polarity as that of the second electrode  120  via the second electrode tab  150 . 
     A center pin penetrating (e.g., extending through) the center of the electrode assembly  100  in the vertical direction may be positioned in a central portion of the electrode assembly  100 . The center pin may support the first electrode tab  140  and the second electrode tab  150 , but the present disclosure is not limited thereto. 
     The case  200  is connected to the first electrode  110  of the electrode assembly  100  and accommodates the electrode assembly  100 . The case  200  has an opening  210  exposing the top of the electrode assembly  100 . Because the first electrode tab  140  is welded to the bottom portion of the case  200  and connected to the first electrode  110  of the electrode assembly  100 , the case  200  has the same polarity as the first electrode  110 . The case  200  may be a cylinder-shaped can for accommodating the electrode assembly  100  in a jelly roll form, but the case  200  is not limited thereto and may have various known forms and/or shapes. The case  200  may accommodate a variety of known electrolyte solutions together with the electrode assembly  100 . An outer surface of the case  200  may be a first electrode terminal of the rechargeable battery  1000 , but the present disclosure is not limited thereto. In such an embodiment, a top surface of the plating layer  410 , which is the outer surface of the terminal portion  400 , may be a second electrode terminal of the rechargeable battery  1000 , but the present disclosure is not limited thereto. The case  200  includes stainless steel, but it is not limited thereto and may include another metal, such as aluminum or nickel and copper. In some embodiments, another plating layer may be coated on the outer surface of the case  200 , but the present disclosure is not limited thereto and various known coating layers may be coated on the outer surface of the case  200 . 
     The opening  210  in the case  200  is covered by the cap plate  300  and the terminal portion  400 . 
       FIG. 3  is an enlarged view of the portion A of  FIG. 2 . 
     Referring to  FIG. 3  together with  FIG. 2 , the cap plate  300  is coupled to the case  200  to cover an outer region of the opening  210 . The cap plate  300  has an opening (e.g., a penetration hole)  310  exposing a central region of the opening  210  and includes an insulation layer  320  coated on the surface of the cap plate  300  corresponding to (e.g., forming or exposed to) the opening  310 . 
     The cap plate  300  is directly coupled to a side wall of the case  200  forming the opening  210  in the case  200  by a welding process and the like to cover the outer region of the opening  210 . The cap plate  300  has a ring shape formed by the opening  310  in the center of the cap plate  300 , but the cap plate  300  is not limited thereto. The cap plate  300  is coupled with the case  200  and has the same polarity as the first electrode  110 . The cap plate  300  includes stainless steel, but it is not limited thereto and may include other metals, such as aluminum or nickel and copper. The outer surface of the cap plate  300  may be a first electrode terminal of the rechargeable battery  1000 , but it is not limited thereto. 
     The insulation layer  320  is coated on a portion of the surface of the cap plate  300  corresponding to the opening  310  and insulates between the cap plate  300  and the terminal portion  400 . The insulation layer  320  includes a first coating layer  321 , a second coating layer  322 , and a third coating layer  323 . The first coating layer  321  is coated on a side surface of the cap plate  300  forming the opening  310 , the second coating layer  322  is coated on an upper surface of the cap plate  300  around the opening  310 , and the third coating layer  323  is coated on a lower surface of the cap plate  300  around the opening  310 . The first coating layer  321 , the second coating layer  322 , and the third coating layer  323  are integrally formed, and the first coating layer  321 , the second coating layer  322 , and the third coating layer  323  directly contact the plating layer  410  of the terminal portion  400 . The first coating layer  321  is completely covered by the plating layer  410  of the terminal portion  400  while a part of the second coating layer  322  and a part of the third coating layer  323  do not overlap (e.g., are not covered by) the plating layer  410 . The second coating layer  322  is coated on only a portion of the top surface of the cap plate  300 , and the third coating layer  323  is coated on only a portion of the lower surface of the cap plate  300 , but the present disclosure is not limited thereto. In other embodiments, each of the second coating layer  322  and the third coating layer  323  may be coated on the entire upper surface and the lower surface of the cap plate  300 , respectively. 
     The insulation layer  320  is formed by depositing an insulative ceramic material resistant to a high temperature environment between the cap plate  300  and the terminal portion  400 , but the present disclosure is not limited thereto. 
     For example, the insulating layer  320  may include an aluminum oxide, a silicon oxide, a silicon nitride, an iron oxide, glass, or the like, but it is not limited thereto. In some embodiments, the insulation layer  320  may include a variety of known materials that are resistant to high temperature environments, except for polymer materials. 
     The terminal portion  400  is connected to the second electrode  120  and joined in an insulated manner to the cap plate  300 . The terminal portion  400  covers the opening  310  in the cap plate  300 . The terminal portion  400  is positioned on the cap plate  300 . The terminal portion  400  covers the central region of the opening  210  in the case  200  at where the opening  310  in the cap plate  300  is exposed. Because the terminal portion  400  covers the central region of the opening  210  and the cap plate  300  covers the outer region of the opening  210 , the opening  210  in the case  200  is completely covered by the terminal portion  400  and the cap plate  300 . The terminal portion  400  tightly seals the electrode assembly  100  together with the case  200  and the cap plate  300 . The terminal portion  400  is coupled to the second electrode tab  150  of the electrode assembly  100  to be connected to the second electrode  120  of the electrode assembly  100 . Thus, the terminal portion  400  has the same polarity as the second electrode  120 . 
     The terminal portion  400  includes the plating layer  410  and a first terminal plate  420 . 
     The plating layer  410  is coated on a surface of the first terminal plate  420  and directly bonded to the insulation layer  320  of the cap plate  300 . The plating layer  410  closes and seals between the first terminal plate  420  and the insulation layer  320  of the cap plate  300  to close and seal between the cap plate  300  and the terminal portion  400 . The plating layer  410  may be coated on the surface of the first terminal plate  420  by using various known electroplating or electroless plating processes and may be directly bonded to the insulation layer  320  of the cap plate  300 . But the present disclosure is not limited thereto. The plating layer  410  directly contacts the first coating layer  321 , the second coating layer  322 , and the third coating layer  323  of the insulating layer  320 . The plating layer  410  completely covers the first coating layer  321  and overlaps a part of (e.g., partially covers) the second coating layer  322  and a part of the third coating layer  323 . The plating layer  410  may include various known conductive materials, such as metal, but it is not limited thereto. 
     The first terminal plate  420  includes a flange portion  421  and a protruding portion  422 . 
     The flange portion  421  is positioned on the cap plate  300  and overlaps the cap plate  300  to cover the opening  310 . The flange portion  421  has a wider area than the protruding portion  422 . The flange portion  421  may have a larger diameter than the protruding portion  422 . The flange portion  421  has a thinner thickness than the protruding portion  422 , but it is not limited thereto. A lower surface of the flange portion  421  contacts the plating layer  410 , and the flange portion  421  is bonded to the insulation layer  320  of the cap plate  300  by the plating layer  410 . The plating layer  410  positioned on an upper surface of the flange portion  421  may be a second electrode terminal of the rechargeable battery  1000 . 
     The protruding portion  422  protrudes from the flange portion  421  and penetrates (e.g., extends into or through) the opening  310 . The protruding portion  422  passes through the opening  310  from the flange portion  421  and is connected to the second electrode  120  through the plating layer  410  coated on the protruding portion  422 . The plating layer  410  positioned on a lower surface of the protruding portion  422  is combined with the second electrode tab  150 . The plating layer  410  positioned on the lower surface of the protruding portion  422  may be welded to the second electrode tab  150 , but the present disclosure is not limited thereto. Because the protruding portion  422  is coupled to the second electrode tab  150  through the plating layer  410 , the first terminal plate  420  and the plating layer  410  including the protruding portion  422  and the flange portion  421  of the terminal portion  400  have the same polarity as the second electrode  120 . 
     The lower surface of the protruding portion  422  connected to the second electrode tab  150  may have a smaller diameter than an upper surface of the flange portion  421 . 
     The protruding portion  422  and the flange portion  421  are integrally formed, but the present disclosure is not limited thereto and different materials may be combined to form the first terminal plate  420 . The first terminal plate  420  includes stainless steel, but it is not limited thereto and may include other metals, such as aluminum or nickel and copper. 
     As described above, in the rechargeable battery  1000  according to an embodiment of the present disclosure, the cap plate  300  is directly coupled to the case  200 , and the insulating bonding between the cap plate  300  and the terminal portion  400  is carried out by the plating layer  410  of the terminal portion  400 , that is directly bonded to the insulation layer  320  including a ceramic material coated on the surface of the cap plate  300  corresponding to the opening  310  of the cap plate  300 , and thus, sealing by the terminal portion  400 , the cap plate  300 , and the case  200  is easily performed even in a high temperature and high humidity environment. 
     For example, a rechargeable battery  1000  that is strong (e.g., durable or resilient) in a high temperature and high humidity environment is provided. 
     Hereinafter, referring to  FIG. 4  and  FIG. 5 , a rechargeable battery according to another embodiment will be described. Hereinafter, parts that are different from the rechargeable battery according to the above-described embodiment will be described. 
       FIG. 4  is a cross-sectional view of a rechargeable battery according to another embodiment, and  FIG. 5  is an enlarged view of the part B of  FIG. 4 . 
     Referring to  FIG. 4  and  FIG. 5 , a rechargeable battery  1002  according to another embodiment includes an electrode assembly  100 , a case  200 , a cap plate  300 , and a terminal portion  400 . 
     The terminal portion  400  is connected to the second electrode  120  and bonded in an insulated manner to the cap plate  300 . The terminal portion  400  covers an opening (e.g., a penetration hole)  310  in the cap plate  300 . The terminal portion  400  is positioned inside the opening  310  in the cap plate  300 . The terminal portion  400  covers a central region of an opening  210  in the case  200  at where the opening  310  in the cap plate  300  is exposed. Because the terminal portion  400  covers the central region of the opening  210  and the cap plate  300  covers an outer region of the opening  210 , the opening  210  in the case  200  is completely covered by the terminal portion  400  and the cap plate  300 . The terminal portion  400  tightly seals the electrode assembly  100  together with the case  200  and the cap plate  300 . The terminal portion  400  is coupled to the second electrode tab  150  of the electrode assembly  100  to be connected to the second electrode  120  of the electrode assembly  100 . Thus, the terminal portion  400  has the same polarity as the second electrode  120 . 
     The terminal portion  400  includes a plating layer  410  and a second terminal plate  430 . 
     The plating layer  410  is coated on a surface of the second terminal plate  430  and directly bonded to an insulation layer  320  of the cap plate  300 . The plating layer  410  closes and seals between the second terminal plate  430  and the insulation layer  320  of the cap plate  300  to close and seal between the cap plate  300  and the terminal portion  400 . The plating layer  410  may be coated on a surface of the second terminal plate  430  by using various known electroplating or electroless plating processes and may be directly bonded to the insulation layer  320  of the cap plate  300 . But the present disclosure is not limited thereto. The plating layer  410  directly contacts the first coating layer  321 , the second coating layer  322 , and the third coating layer  323  of the insulation layer  320 . The plating layer  410  completely covers the first coating layer  321 , and overlaps a part of (e.g., partially covers) the second coating layer  322  and a part of the third coating layer  323 . The plating layer  410  may include various known conductive materials, such as a metal, but it is not limited thereto. 
     The second terminal plate  430  is positioned inside the opening  310  in the cap plate  300  to cover the opening  310  in the cap plate  300 . The second terminal plate  430  has a smaller diameter than a diameter of the opening  310 . The second terminal plate  430  is bonded to the insulation layer  320  of the cap plate  300  by the plating layer  410 . The plating layer  410  positioned on a lower surface of the second terminal plate  430  is coupled with the second electrode tab  150 , and the plating layer  410  positioned on an upper surface of the second terminal plate  430  may be a second electrode terminal of the rechargeable battery  1002 . The plating layer  410  positioned on a lower surface of the second terminal plate  430  may be welded to the second electrode tab  150 , but it is not limited thereto. Because the second terminal plate  430  is coupled with the second electrode tab  150  through the plating layer  410 , the second terminal plate  430  and the plating layer  410  of the terminal portion  400  have the same polarity as the second electrode  120 . The second terminal plate  430  includes stainless steel, but this is not restrictive, and the second terminal plate  430  may include other metals, such as aluminum or nickel and copper. 
     As described above, in the rechargeable battery  1002  according to an embodiment of the present disclosure, the cap plate  300  is directly coupled to the case  200 , and the insulating bonding between the cap plate  300  and the terminal portion  400  is carried out by the plating layer  410  of the terminal portion  400  that is directly bonded to the insulation layer  320  including a ceramic material coated on the surface of the cap plate  300  corresponding to the opening  310  in the cap plate  300 , and thus, sealing by the terminal portion  400 , the cap plate  300 , and the case  200  is easily performed even in a high temperature and high humidity environment. 
     For example, a rechargeable battery  1002  that is strong (e.g., durable or resilient) in a high temperature and high humidity environment is provided. 
     Hereinafter, referring to  FIG. 6  and  FIG. 7 , a rechargeable battery according to another embodiment will be described. 
     Hereinafter, parts that are different from the rechargeable battery according to the above-described embodiments will be described. 
       FIG. 6  is a cross-sectional view of a rechargeable battery according to another embodiment, and  FIG. 7  is an enlarged view of the part C of  FIG. 6 . 
       FIG. 6  and referring to  FIG. 7 , a rechargeable battery  1003  according to another embodiment includes an electrode assembly  100 , a case  200 , a cap plate  300 , and a terminal portion  400 . 
     The terminal portion  400  is connected to the second electrode  120  and is bonded in an insulated manner to the cap plate  300 . The terminal portion  400  covers an opening (e.g., a penetration hole)  310  in the cap plate  300 . The terminal portion  400  fills the opening  310  in the cap plate  300 . The terminal portion  400  covers a central region of an opening  210  in the case  200  to which the opening  310  in the cap plate  300  is exposed. Because the terminal portion  400  covers the central region of the opening  210  and the cap plate  300  covers an outer region of the opening  210 , the opening  210  in the case  200  is completely covered by the terminal portion  400  and the cap plate  300 . 
     The terminal portion  400  tightly seals the electrode assembly  100  together with the case  200  and the cap plate  300 . The terminal portion  400  is coupled to the second electrode tab  150  of the electrode assembly  100  to be connected to the second electrode  120  of the electrode assembly  100 . The terminal portion  400  has the same polarity as the second electrode  120 . 
     The terminal portion  400  includes a plating layer  410 . 
     The plating layer  410  completely fills the opening  310  in the cap plate  300  and is directly bonded to an insulation layer  320  of the cap plate  300 . The plating layer  410  closes and seals the opening  310  between the insulation layer  320  of the cap plate  300  to close and seal the cap plate  300  and the terminal portion  400 . The opening  310  in the cap plate  300  filled with the plating layer  410  may have a smaller diameter than the opening  310  in the rechargeable battery  1000  according to an above-mentioned embodiment or the opening  310  in the rechargeable battery  1002  according to the other embodiment, but it is not limited thereto. The plating layer  410  may be directly bonded to the insulation layer  320  of the cap plate  300  by completely filling the opening  310  in the cap plate  300  by using various known electroplating or electroless plating processes, but it is not limited thereto. The plating layer  410  directly contacts the first coating layer  321 , the second coating layer  322 , and the third coating layer  323  of the insulation layer  320 . The plating layer  410  completely covers the first coating layer  321 , and overlaps a part of (e.g., partially covers) the second coating layer  322  and a part of the third coating layer  323 . The plating layer  410  includes a first plating portion  411 , a second plating portion  412 , and a third plating portion  413 . 
     The first plating portion  411  fills the opening  310  and directly contacts the first coating layer  321 , the second plating portion  412  directly contacts the second coating layer  322  by covering an upper surface of the cap plate  300  from the first plating portion  411 , and the third plating portion  413  directly contacts the third coating layer  323  by covering a lower surface of the cap plate  300  from the first plating portion  411 . The first plating portion  411 , the second plating portion  412 , and the third plating portion  413  are integrally formed, but plating layer  410  is not limited thereto. At least one of the first plating portion  411 , the second plating portion  412 , and the third plating portion  413  may contain a different conductive material than the other portion(s). For example, at least one of the first plating portion  411 , the second plating portion  412 , and the third plating portion  413  may be formed as a plating seed layer and the other portion(s) may be formed as a plating growth layer, but the present disclosure is not limited thereto. 
     The terminal portion  400  is positioned inside the plating layer  410   310  in the cap plate  300  by the plating layer  410 . The third plating portion  413  of the plating layer  410  is coupled with the second electrode tab  150 , and the second plating portion  412  may be a second electrode terminal of the rechargeable battery  1003 . The third plating portion  413  of the plating layer  410  may be welded to the second electrode tab  150 , but it is not limited thereto. Because the plating layer  410  is coupled with the second electrode tab  150 , the terminal portion  400  has the same polarity as that of the second electrode  120 . The plating layer  410  may include various known conductive materials, such as a metal, but it is not limited thereto. 
     As described above, in the rechargeable battery  1003  according to an embodiment of the present disclosure, the cap plate  300  is directly coupled to the case  200 , and the insulating bonding between the cap plate  300  and the terminal portion  400  is carried out by the plating layer  410  of the terminal portion  400  that is directly bonded to the insulation layer  320  including a ceramic material coated on the surface of the cap plate  300  corresponding to the opening  310  in the cap plate  300 , and thus, sealing by the terminal portion  400 , the cap plate  300 , and the case  200  is easily performed even in a high temperature and high humidity environment. 
     For example, a rechargeable battery  1003  that is strong (e.g., durable or resilient) in a high temperature and high humidity environment is provided. 
     While the present disclosure has been described in connection with what is presently considered to be practical embodiments, it is to be understood that the present disclosure is not limited to the disclosed embodiments. The present disclosure is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims and their equivalents. 
     DESCRIPTION OF SOME REFERENCE NUMERALS 
     
         
         electrode assembly  100   
         case  200   
         cap plate  300   
         insulation layer  320   
         terminal portion  400   
         plating layer  410