Abstract:
A rechargeable battery includes an electrode assembly, a first current collecting plate and a second current collecting plate spaced apart from each other and electrically connected to first and second electrode uncoated regions n the electrode assembly, a case receiving the electrode assembly, a cap plate sealing the case, a first electrode terminal and a second electrode terminal extending through the cap plate and electrically connected to the first and second current collecting plates, a first retainer adjacent to the cap plate and coupled to firsts regions of the first and second current collecting plates, and a second retainer coupled to second regions of the first and second current collecting plates or to the first and second electrode uncoated regions, the first and second regions of the first and second current collecting plates being different from each other.

Description:
BACKGROUND 
     1. Field of the Invention 
     Embodiments relate to a rechargeable battery. 
     2. Description of the Related Art 
     Unlike primary batteries, which cannot be recharged, rechargeable batteries can be repeatedly charged and discharged. Low capacity rechargeable batteries that use single battery cells may be used as power sources for various portable electronic devices, e.g., cellular phones and camcorders. High capacity rechargeable batteries that use tens of battery cells connected to each other in a battery pack may be used as power sources for driving motors, e.g., electric scooters and hybrid electric vehicles (HEV). 
     Rechargeable batteries may be classified into different types, e.g., cylindrical and prismatic types. A unit battery includes an electrode assembly having positive and negative electrodes and a separator interposed between the positive and negative electrodes, a case for receiving the electrode assembly, and a cap assembly for sealing the case. Positive and negative terminals outwardly extending from the cap assembly are electrically connected to the positive and negative electrodes, respectively. 
     SUMMARY 
     Embodiments provide a rechargeable battery with first and second retainers connected to the current collecting plates of an electrode assembly, thereby affixing the electrode assembly and preventing damage thereto due to external impacts. 
     Embodiments also provide a rechargeable battery with first and second retainers connected to the current collecting plates of an electrode assembly, thereby stabilizing connection therein and improving electrical reliability by preventing electrical shorts. 
     Embodiments further provide a rechargeable battery with an elastic plate coupled to a retainer connected to the current collecting plates of an electrode assembly, thereby allowing the elastic plate to serve as an elastic body during welding and improving durability by absorbing vibration energy. 
     According to an embodiment, a rechargeable battery is provided, including an electrode assembly including a first electrode having a first electrode uncoated region at a first end of the electrode assembly, a second electrode having a second electrode uncoated region at a second end of the electrode assembly opposite the first end, and a separator interposed between the first and second electrodes, a first current collecting plate and a second current collecting plate spaced apart from each other, the first and second current collecting plates being electrically connected to the first and second electrode uncoated regions, respectively, a case configured to receive the electrode assembly, the first current collecting plate, and the second current collecting plate, a cap plate configured to seal the case, a first electrode terminal and a second electrode terminal extending through the cap plate, the first and second electrode terminals being electrically connected to the first and second current collecting plates, respectively, a first retainer adjacent to the cap plate, the first retainer being coupled to a first region of each of the first and second current collecting plates, and a second retainer coupled to a second region of each of the first and second current collecting plates or to each of the first and second electrode uncoated regions, the second regions of the first and second current collecting plates being different from the first regions of the of the first and second current collecting plates. 
     The first regions of the first and second current collecting plates may be connected to the first and second electrode terminals, respectively, and the second regions of the first and second current collecting plates may extend from respective first regions, the second regions being bent with respect to the first regions. 
     The first retainer may include a first receiving part and a second receiving part, each of the first and second receiving parts having a receiving hole, and the first region of each of the first and second current collecting plates being inserted into a respective receiving hole, and a first supporting part connecting the first receiving part and the second receiving part. 
     The first supporting part may be perpendicular to each of the first receiving part and the second receiving part. 
     Each of the first receiving part and the second receiving part may further include outer sidewalls and inner sidewalls, the inner sidewalls having an opening hole open in a vertical direction, and left sidewalls and right sidewalls, the left and right sidewalls connecting the outer sidewalls and the inner sidewalls. 
     The first electrode uncoated region and the second electrode uncoated region may be connected to the first current collecting plate and the second current collecting plate through the opening holes of respective first and second receiving parts of the first retainer. 
     The second retainer may include a first connection part and a second connection part, each of the first and second connection parts having coupling holes, and the second regions of each of the first and second current collecting plates being inserted into respective coupling holes, and a second supporting part connecting the first connection part and the second connection part. 
     The second supporting part may be perpendicular to each of the first connection part and the second connection part. 
     Each of the first connection part and the second connection part may include outer sidewalls and inner sidewalls, the inner sidewalls including slits, left and right sidewalls connecting the outer sidewalls and the inner sidewalls, and pillar parts connecting the outer sidewalls and the inner sidewalls, the pillars being arranged to have the slits in left and right sides thereof in a vertical direction. 
     The second retainer may further include a first coupling hole and a second coupling hole at respective first and second sides of the pillar parts. 
     The pillar parts may further include protrusions on at least one side surface of each pillar part, and the second regions of the first and second current collecting plates may include coupling holes. 
     The protrusions may be coupled to the coupling holes. 
     The second supporting part tightly may contact a bottom surface of the case. 
     The second supporting part may include at least one opening hole. 
     An elastic plate may be mounted in the opening hole. 
     The elastic plate may include a downwardly convex round part, and an edge part fixed to the second supporting part of the second retainer. 
     The elastic plate may further include a stepped portion at an end of the edge part, at least one end of the elastic plate being coupled to the stepped portion. 
     The first connection part and the second connection part may include a first sidewall and a second sidewall, respectively, and the first sidewall and the second sidewall may surround either side surfaces of the electrode assembly positioned under the second regions of the first and second current collecting plates. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above and other features and advantages will become more apparent to those of ordinary skill in the art by describing in detail exemplary embodiments with reference to the attached drawings, in which: 
         FIG. 1  illustrates a perspective view of a rechargeable battery according to an embodiment; 
         FIG. 2  illustrates a cross-sectional view of the rechargeable battery along line I-I′ of  FIG. 1 ; 
         FIG. 3  illustrates a perspective view of a first retainer shown in  FIG. 2 ; 
         FIG. 4  illustrates a perspective view of a second retainer shown in  FIG. 2 ; 
         FIGS. 5A to 5D  illustrate perspective views of a process of assembling a rechargeable battery according to an embodiment; 
         FIG. 6  illustrates a cross-sectional view of a rechargeable battery according to another embodiment; and 
         FIG. 7  illustrates an enlarged cross-sectional view of a portion ‘A’ of  FIG. 6 . 
     
    
    
     DETAILED DESCRIPTION 
     Korean Patent Application No. 10-2011-0015391, filed on Feb. 22, 2011, in the Korean Intellectual Property Office, and entitled: “Rechargeable Battery,” is incorporated by reference herein in its entirety. 
     Example embodiments will now be described more fully hereinafter with reference to the accompanying drawings; however, they may be embodied in different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. 
     In the drawing figures, the dimensions of layers and regions may be exaggerated for clarity of illustration. It will also be understood that when a layer or element is referred to as being “on” another element or substrate, it can be directly on the other element or substrate, or intervening elements may also be present. In addition, it will also be understood that when an element is referred to as being “between” two elements, it can be the only element between the two elements, or one or more intervening elements may also be present. Like reference numerals refer to like elements throughout. 
     Hereinafter, exemplary embodiments will be described in detail with reference to  FIGS. 1-4 .  FIG. 1  is a perspective view of a rechargeable battery according to an embodiment  FIG. 2  is a cross-sectional view of the rechargeable battery along line I-I′ of  FIG. 1 ,  FIG. 3  is a perspective view of a first retainer shown in  FIG. 2 , and  FIG. 4  is a perspective view of a second retainer shown in  FIG. 2 . 
     Referring to  FIGS. 1 and 2 , a rechargeable battery  100  according to example embodiments may include an electrode assembly  110 , a first terminal  120 , a second terminal  130 , a case  140 , and a cap assembly  150 . The rechargeable battery  100  may further include first and second retainer  170  and  180 , as will be described in more detail below. 
     The electrode assembly  110  may be formed by winding a stack of a first electrode plate  111 , a separator  113 , and a second electrode plate  112  or by stacking the stack together. Here, the first electrode plate  111  may operate as a negative electrode and the second electrode plate  112  may operate as a positive electrode, or vice versa. The electrode assembly  110  may be stacked in a substantially jelly-roll configuration. 
     The first electrode plate  111  may be formed by coating a first electrode active material, e.g., graphite or carbon, on a first electrode collector formed of a metal foil, e.g., made of copper or nickel, and includes a first electrode uncoated region  111   a , i.e., a region not coated with the first electrode active material, formed at a first end of the first electrode plate  111 . However, the material of the first electrode plate  111  is not limited thereto. The first electrode uncoated region  111   a  becomes a path of the flow of current between the first electrode plate  111  and the outside thereof. 
     The second electrode plate  112  may be formed by coating a second electrode active material, e.g., a transition metal oxide, on a second electrode collector formed of a metal foil, e.g., made of aluminum, and includes a second electrode uncoated region  112   a , i.e., a region not coated with a second electrode active material, formed at a second end of the second electrode plate  111 , opposite to the first end of the first electrode plate  111 . However, the material of the second electrode plate  112  is not limited thereto. The second electrode uncoated region  112   a  becomes a path of the flow of current between the second electrode plate  112  and the outside thereof. 
     The separator  113  may be interposed between the first electrode plate  111  and the second electrode plate  112  for preventing a short-circuit therebetween and for allowing movement of lithium ions. The separator  113  may be formed of, e.g., polyethylene (PE), polypropylene (PP), or a composite film of PE and PP. However, the material of the separator  113  is not limited thereto. 
     The electrode assembly  110  is accommodated in the case  140  with electrolyte. The electrolyte may include an organic solvent, e.g., ethylene carbonate (EC), propylene carbonate (PC), diethyl carbonate (DEC), ethyl methyl carbonate (EMC), or dimethyl carbonate (DMC), and a lithium salt, e.g., LiPF6 or LiBF4. The electrolyte may be a liquid, solid, and/or gel electrolyte. 
     A first terminal  120  and a second terminal  130  may be electrically connected to the first electrode plate  111  and the second electrode plate  112  at opposing ends of the electrode assembly  110 , respectively. That is to say, the first terminal  120  and the second terminal  130  connected to the first uncoated region  111   a  of the first electrode plate  111  and the second uncoated region  112   a  of the second electrode plate  112 , respectively, may be coupled to the opposing ends of the electrode assembly  110 . 
     The first terminal  120  is generally made of a metal or equivalents thereof and is electrically connected to the first electrode plate  111 . The first terminal  120  may include a first collector plate  121 , a first electrode terminal  122 , and a first terminal plate  123 . 
     The first collector plate  121  contacts the first electrode uncoated region  111   a  protruding toward one end of the electrode assembly  110 . For example, the first collector plate  121  may be welded to the first electrode uncoated region  111   a . The first collector plate  121  may include a first region  121   a  and a second region  121   b  ( FIG. 5A ) and may be formed in an inverted-L shape, i.e., r-shape. The first region  121   a  may be shaped as a plate and may be connected to the first electrode terminal  122  ( FIG. 5A ). A terminal hole  121   d  may be formed at one side of the first region  121   a . The first electrode terminal  122  may be inserted into and engaged with the terminal hole  121   d . The second region  121   b  may extend from the first region  121   a  in a first direction, i.e., toward the first electrode uncoated region  111   a . The first collector plate  121  may be made of, e.g., copper or a copper alloy, but not limited thereto. A coupling hole  121   c  ( FIG. 5A ) having a predetermined size may be formed in the second region  121   b  of the first collector plate  121 . The coupling hole  121   c  may be engaged with a protrusion part  181   h  ( FIG. 4 ) formed at one side surface or both side surfaces of a pillar part  181   g  ( FIG. 4 ) of the second retainer  180 , which will be described later. 
     The first electrode terminal  122  upwardly protrudes and extends by a predetermined length while extending through a cap plate  151  to be described later, and is electrically connected to the first collector plate  121  under the cap plate  151 . The first electrode terminal  122  protrudes and extends by a predetermined length upwardly with respect to the cap plate  151 , and includes a laterally extending flange  122   a  that may be formed under the cap plate  151  to prevent the first electrode terminal  122  from being dislodged from the cap plate  151 . 
     A region of the first electrode terminal  122  formed under the flange  122   a  is fitted into the terminal hole  121   d  of the first collector plate  121  to be welded. A region of the first electrode terminal  122  formed above the flange  122   a  is fixed to the first terminal plate  123 . That is to say, the region of the first electrode terminal  122  formed above the flange  122   a  includes a first body part  122   b  extending through the cap plate  151 , and a first fastening part  122   c  threaded to the first terminal plate  123  at a top end of the first body part  122   b . Here, a thread is formed on an outer circumference of the first fastening part  122   c . Alternatively, the first fastening part  122   c  may be riveted to the first terminal plate  123 . In addition, the first electrode terminal  122  may be electrically insulated from the cap plate  151 . The first electrode terminal  122  may be made of, e.g., at least one of copper, a copper alloy, and equivalents thereof. However, the material of the first electrode terminal  122  is not limited thereto. 
     The first terminal plate  123  may be a nut shaped of a substantially hexagonal prism to be engaged with the first fastening part  122   c . Alternatively, the first terminal plate  123  may be shaped such that a throughhole (not shown) may be centrally formed substantially in a vertical direction to allow the first electrode terminal  122  to extend therethrough to be engaged, and a groove (not shown) having a predetermined depth is formed substantially on its top portion to allow the first fastening part  122   c  to be safely placed therein. The first terminal plate  123  may be made of, e.g., at least one of stainless steel, copper, a copper alloy, aluminum, an aluminum alloy, and equivalents thereof, but not limited thereto. The first terminal plate  123  and the cap plate  151  are insulated from each other. 
     The second terminal  130  may also be made of a metal or equivalents thereof and may be electrically connected to the second electrode plate  112 . The second terminal  130  may include a second collector plate  131 , a second electrode terminal  132 , and a second terminal plate  133 . For example, the second terminal  130  may have the same shape as the first terminal  120 , and a detailed description thereof will be omitted. The second collector plate  131  and the second electrode terminal  132  may be generally made of, e.g., at least one of aluminum, an aluminum alloy, and equivalents thereof, but not limited thereto. In addition, the second terminal plate  133  may be made of, e.g., at least one of stainless steel, aluminum, an aluminum alloy, copper, a copper alloy, and equivalents thereof, but not limited thereto. The second terminal plate  133  may be electrically connected to the cap plate  151 , and thus the case  140  and the cap plate  151 , which will be described later, may have the same polarity (e.g., a positive polarity) as the second terminal  130 . 
     As illustrated in  FIG. 2 , the first retainer  170  may be connected to the first regions  121   a  and  131   a  of the first collector plate  121  and the second collector plate  131 , respectively. In other words, the first retainer  170  may be connected to upper portions of the first collector plate  121  and the second collector plate  131 , thereby increasing stability thereof. Similarly, the second retainer  180  may be connected to the second regions  121   b  and  131   b . In other words, the second retainer  180  may be connected to bottom portions of the first collector plate  121  and the second collector plate  131 , thereby further increasing stability thereof. It is noted, however, that while  FIG. 2  illustrates that the second retainer  180  is connected to the second regions  121   b  and  131   b  of the first collector plate  121  and the second collector plate  131 , example embodiments are not limited thereto. For example, the second retainer  180  may be connected to the first electrode uncoated region  111   a  and the second electrode uncoated region  112   a . In another example, the second retainer  180  may be configured to surround exterior sides of the second regions  121   b  and  131   b  of the first collector plate  121  and the second collector plate  131 . 
     In detail, as illustrated in  FIG. 3 , the first retainer  170  may include a first receiving part  171 , a second receiving part  172 , and a first supporting part  173 . 
     The first receiving part  171  and the second receiving part  172  may include receiving holes  171   e  and  172   e  ( FIG. 2 ) into which the first regions  121   a  and  131   a  of the first collector plate  121  and the second collector plate  131  are inserted. The first receiving part  171  and the second receiving part  172  may include outer sidewalls  171   a  and  172   a , inner sidewalls  171   b  and  172   b , and left and right sidewalls  171   c ,  171   d ,  172   c  and  172   d  connecting the outer sidewalls  171   a  and  172   a  and the inner sidewalls  171   b  and  172   b . Top ends  171   f  and  172   f  of the outer sidewalls  171   a  and  172   a  are higher than the first supporting part  173  to cover the exterior sides of the first collector plate  121  and the second collector plate  131 . In addition, the inner sidewalls  171   b  and  172   b  include opening holes  171   g  and  172   g  opened in an up-down direction, i.e., along a vertical direction. The opening holes  171   g  and  172   g  provide spaces in which the first regions  121   a  and  131   a  of the first collector plate  121  and the second collector plate  131  are received in the first receiving part  171  and the second receiving part  172 , thereby allowing the first collector plate  121  and the second collector plate  131  to be assembled with the first receiving part  171  and the second receiving part  172  more easily. In addition, the first electrode uncoated region  111   a  and the second electrode uncoated region  112   a  are connected to the first collector plate  121  and the second collector plate  131  through the opening holes  171   g  and  172   g.    
     The first supporting part  173  may be configured to connect the first receiving part  171  and the second receiving part  172 . Here, locations where the first receiving part  171  and the second receiving part  172  are connected to the first supporting part  173  may have curved sections. That is to say, portions where the first receiving part  171  and the second receiving part  172  are connected to the first supporting part  173  are curved, so that the electrode assembly  110  is received therein. In addition, the first supporting part  173  may be higher than the inner sidewalls  171   b  and  172   b  of the first receiving part  171  and the second receiving part  172 , so that the outer sidewalls  171   a  and  172   a  of the first receiving part  171  and the second receiving part  172  may surround outer sidewalls of the first collector plate  121  and the second collector plate  131 . In addition, the first supporting part  173  may be flatly formed, so that a flat top surface thereof may tightly contact a lower insulation member  156  positioned on a bottom surface of the cap plate  151 . That is to say, the first supporting part  173  may be formed substantially perpendicularly to the first receiving part  171  and the second receiving part  172 . 
     As illustrated in  FIG. 4 , the second retainer  180  may include a first connection part  181 , a second connection part  182 , and a second supporting part  183 . 
     The first connection part  181  and the second connection part  182  have coupling holes  181   e  and  182   e  into which the second regions  121   b ,  131   b  of the first collector plate  121  and the second collector plate  131  are inserted. The first connection part  181  and the second connection part  182  may include outer sidewalls  181   a  and  182   a , inner sidewalls  181   b  and  182   b , left and right walls  181   c ,  181   d ,  182   c , and  182   d  connecting the outer sidewalls  181   a  and  182   a  and the inner sidewalls  181   b  and  182   b , respectively, and pillar parts  181   g  and  182   g  connecting the outer sidewalls  181   a  and  182   a  and the inner sidewalls  181   b  and  182   b.    
     Here, slits  181   f  and  182   f  are formed in the inner sidewalls  181   b  and  182   b  in left and right sides of the pillar parts  181   g  and  182   g  in an up-down direction. The slits  181   f  ad  182   f  provide spaces in which the second region  121   b  and  131   b  of the first collector plate  121  and the second collector plate  131  are received in the first connection part  181  and the second connection part  182 , thereby allowing the first collector plate  121  and the second collector plate  131  to be assembled with the first connection part  181  and the second connection part  182  more easily. That is to say, the second retainer  180  includes the slits  181   f  ad  182   f  formed in the left and right sides of the pillar parts  181   g  and  182   g . As a result, the first coupling hole  181   e  and the second coupling hole  182   e  are formed at opposing sides of the pillar parts  181   g  and  182   g . However, example embodiments do not limit the slits to those illustrated herein. For example, the slits  181   f  ad  182   f  may be formed to correspond to the second regions of the first collector plate  121  and the second collector plate  131 . In addition, the first electrode uncoated region  111   a  and the second electrode uncoated region  112   a  may be connected to the first collector plate  121  and the second collector plate  131  through the first coupling hole  181   e  and the second coupling hole  182   e . Further, protrusions  181   h  and  182   h  may be formed on one side surface or opposing side surfaces of the pillar parts  181   g  and  182   g , and the coupling holes  121   c ,  131   c  may be formed in the second regions of the first collector  121  and the second collector plate  131 . That is to say, the protrusion  181   h  and  182   h  outwardly protrude from one side surface or opposing side surfaces of the pillar parts  181   g  and  182   g . The protrusions  181   h  and  182   h  may be engaged with the coupling holes  121   c  and  131   c  formed in the second regions  121   b  and  131   b  of the first collector plate  121  and the second collector plate  131 , so that the second regions  121   b  and  131   b  of the first collector plate  121  and the second collector plate  131  may be assembled with the second retainer  180 . 
     The first connection part  181  and the second connection part  182  may be a first sidewall ( 181  of  FIG. 6 ) and a second sidewall ( 182  of  FIG. 6 ) formed to surround opposing side surfaces of the electrode assembly  110  positioned under the second regions  121   b  and  131   b  of the first collector plate  121  and the second collector plate  131 . 
     The second supporting part  183  may be formed to connect bottom portions of the first connection part  181  and the second connection part  182 . Here, portions where the first connection part  181  and the second connection part  182  are connected with the second supporting part  183  may have curved sections. That is to say, the portions where the first connection part  181  and the second connection part  182  are connected with the second supporting part  183  are curved, so that the electrode assembly  110  is received inside. In addition, the second supporting part  183  may be flatly formed, so that its flat bottom surface tightly contacts a bottom surface of the case  140 . That is to say, the second supporting part  183  may be formed substantially perpendicularly to the first connection part  181  and the second connection part  182 . Here, a top surface of the second supporting part  183  may tightly contact a bottom surface of the electrode assembly  110 . 
     The case  140  may receive the electrode assembly  110 , the first electrode terminal  122 , and the second electrode terminal  132 . The electrode assembly  110  may be received in the case  140  together with an electrolyte. 
     The cap assembly  150  may be coupled to the case  140 . Specifically, the cap assembly  150  may include a cap plate  151 , a seal gasket  152 , a plug  153 , a safety vent  154 , an upper insulation member  155 , and a lower insulation member  156 . The cap plate  151  seals an opening of the case  140  and may be made of the same material as the case  140 . 
     The seal gasket  152  is formed to seal portions between the first electrode terminal  122  and the cap plate  151 , and between the second electrode terminal  132  and the cap plate  151  using an insulating material. 
     The plug  153  seals an electrolyte injection hole  151   a  of the cap plate  151 . The safety vent  154  may be installed in a vent hole  151   b  of the cap plate  151  and may include a notch  154   a  to be opened at a predetermined pressure. 
     The upper insulation member  155  is formed between each of the first terminal plate  123  and the second terminal plate  133  and the cap plate  151 . The upper insulation member  155  insulates each of the first terminal plate  123  and the second terminal plate  133  from the cap plate  151 . 
     The lower insulation member  156  is formed between each of the first collector plate  121  and the second collector plate  131  and the cap plate  151 . The lower insulation member  156  prevents unnecessary electric shorts from being generated. In addition, the lower insulation member  156  may also be formed between each of the first electrode terminal  122  and the second electrode terminal  132  and the cap plate  151  to prevent electric shorts from being generated between each of the first electrode terminal  122  and the second electrode terminal  132  and the cap plate  151 . 
     Therefore, the rechargeable battery according to the embodiment may fix, e.g., stabilize, the electrode assembly by coupling the first and second retainers to the top and bottom portions, respectively, of the collector plate. As such, the electrode assembly may be prevented from being damaged due to external impacts, and may exhibit improved electrical reliability due to preventing electric shorts. 
       FIGS. 5A to 5D  are perspective views illustrating a process of assembling a rechargeable battery according to an embodiment. First, it is assumed that the first terminal  120  and the second terminal  130  are assembled with the cap assembly  150 . 
     Referring to  FIG. 5A , the first retainer  170  is placed under the first collector plate  121  and the second collector plate  131 , and is moved toward first regions  121   a  and  131   a  of the first collector plate  121  and the second collector plate  131  to be engaged with the receiving holes  171  and  172  of the first retainer  170 . Here, the outer sidewalls  171   a  and  172   a  of the first receiving part  171  and the second receiving part  172  tightly contact the bottom surface of the cap plate  151 , and the inner sidewalls  171   b  and  172   b  of the receiving holes  171  and  172  tightly contact bottom surfaces of the first regions  121   a  and  131   a  of the first collector plate  121  and the second collector plate  131 . 
     Referring to  FIG. 5B , the electrode assembly  110  is placed in the bottom portions of the first collector plate  121  and the second collector plate  131  connected with the first retainer  170 . That is, the electrode assembly  110  is coupled to an internal space formed by the first receiving part  171  and the second receiving part  172  of the first retainer  170  and the first supporting part  173 . That is to say, the electrode assembly  110  may be tightly contacted to the inside of the first retainer  170 , so the first and second electrode uncoated regions  111   a  and  112   a  of the electrode assembly  110  may be welded to the first collector plate  121  and the second collector plate  131 . For example, the top surface of the electrode assembly  110  may be tightly coupled to the first supporting part  173  of the first retainer  170 . 
     Referring to  FIG. 5C , the second retainer  180  is placed in the bottom portions of the first collector plate  121  and the second collector plate  131  connected with the electrode assembly  110 , and is moved toward the second regions  121   b  and  131   b  of the first collector plate  121  and the second collector plate  131  to be engaged with the coupling holes  121   c  and  131   c  of the second retainer  180 . The bottom surface of the electrode assembly  110  may tightly contact the second supporting part  183  of the second retainer  180 . 
     Referring to  FIG. 5D , the first collector plate  121  and the second collector plate  131  connected with the first retainer  170  and the second retainer  180  are received in the case  140 . The internal bottom surface of the case  140  may tightly contact the bottom surface of the second supporting part  183 . 
       FIG. 6  is a cross-sectional view of a rechargeable battery according to another embodiment.  FIG. 7  is an enlarged cross-sectional view of a portion ‘A’ of  FIG. 6 . 
     Referring to  FIGS. 6 and 7 , the rechargeable battery according to the embodiment may include at least one opening hole  185  formed in the second supporting part  183  of the second retainer  180 . The opening hole  185  may include an elastic plate  184  having an elastic force. In addition, the second retainer  180  may include first and second connection parts  181 ′ and  182 ′ that are configured to surround opposing side surfaces of the electrode assembly  110  positioned under second region  121   b  and  131   b  of the first collector plate  121  and the second collector plate  131 , e.g., extend along opposite surfaces of the electrode assembly  110  and in contact therewith. As the second supporting part  183  connects the first connection part  181 ′ and the second connection part  182 ′, the opposing side surfaces of the electrode assembly  110  may be surrounded by the first sidewall  181 ′ and the second sidewall  182 ′. As such, the electrode assembly  110  may be stabilized, so damaged to the electrode assembly  110  due to external impacts may be prevented or substantially minimized. 
     The elastic plate  184  may include a downwardly convex round part  184   b  and an edge part  184   a . The round part  184   b  may be formed to contact a bottom surface of the case  140 . When an external vibration is applied to the case  140 , the round part  184  absorbs vibration energy, thereby improving durability. The edge part  184   a  may be configured such that opposite ends of the elastic plate  184  are fixed to the second supporting part  183  of the second retainer  180 . Therefore, in order to allow the opposite ends of the elastic plate  184  to be fixed to the second supporting part  183  of the second retainer  180 , a stepped portion  183   a  may be formed at an end of the edge part  184   a  to be connected with the opposite ends of the elastic plate  184 . Therefore, in the rechargeable battery according to the embodiment, the elastic plate  184  may be coupled to the second retainer  180 , thereby improving durability by imparting elasticity during welding and absorbing vibration energy. 
     As described above, in the rechargeable battery according to example embodiments, an electrode assembly can be fixed and damages due to external impacts can be prevented by coupling first and second retainers to a collector plate, thereby improving electrical reliability by preventing electrical shorts. In addition, an elastic plate may be allowed to serve as an elastic body during welding by coupling an elastic plate to a second retainer, and durability of the rechargeable battery can be improved by absorbing vibration energy. 
     Example embodiments have been disclosed herein, and although specific terms are employed, they are used and are to be interpreted in a generic and descriptive sense only and not for purpose of limitation. Accordingly, it will be understood by those of skill in the art that various changes in form and details may be made without departing from the spirit and scope as set forth in the following claims.