CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims priority to and the benefit of Korean Patent Application No. 10-2015-0049233 filed in the Korean Intellectual Property Office on Apr. 7, 2015, the entire content of which is incorporated herein by reference. 
       BACKGROUND 
       [0002]    1. Field 
         [0003]    Aspects of embodiments of the present invention relate to a rechargeable battery. 
         [0004]    2. Description of the Related Art 
         [0005]    A rechargeable battery differs from a primary battery in that it can be repeatedly charged and discharged, while the latter may be incapable of being recharged. A low-capacity rechargeable battery is used in small portable electronic devices such as mobile phones, notebook computers, and camcorders, while a high-capacity rechargeable battery is widely used as a power source for driving a motor of a hybrid vehicle. 
         [0006]    A rechargeable battery generally includes, for example, a case for accommodating an electrode assembly, and a cap assembly for closing and sealing the case. In order to assemble such a rechargeable battery, an uncoated region formed at one side of the electrode assembly may be connected to a current collecting member combined to the cap assembly. 
         [0007]    On the other hand, the current collecting member is generally combined to the cap assembly by a caulking method. However, when a caulked part is weak, the current collecting member may be twisted. Such twist may cause an increase in contact resistance and thus generate heat, making it difficult to improve high power output performance. 
         [0008]    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 constitute prior art. 
       SUMMARY 
       [0009]    Aspects of embodiments of the present invention relate to a rechargeable battery, and a reusable rechargeable battery. 
         [0010]    According to aspects of embodiments of the present invention, a rechargeable battery may prevent or reduce instances of deformation of a current collecting member. 
         [0011]    According to some example embodiments, a rechargeable battery includes: an electrode assembly comprising: a first electrode and a second electrode; a case comprising an opening at a side of the case, the case accommodating the electrode assembly; a cap assembly comprising a cap plate covering the opening of the case, a first terminal protruding out of the cap plate and electrically coupled to a first electrode, and a second terminal protruding out of the cap plate and electrically coupled to a second electrode; a first current collector coupled to a lower part of the cap assembly and having a first side electrically connected to the first terminal and a second side coupled to the first electrode; and a deformation preventer coupled to the lower part of the cap assembly and formed to accommodate a part of the first current collector. 
         [0012]    The cap assembly may include a mounting groove recessed with a size corresponding to the deformation preventer, the deformation preventer may include a body in the mounting groove, and the deformation preventer may further include a fixing groove recessed to accommodate the part of the first current collector at a lateral side of the body. 
         [0013]    A lower part of the body of the deformation preventer may be in the mounting groove, and the fixing groove may be at an upper part of the body that is not in the mounting groove. 
         [0014]    A width of the fixing groove may be equal to a width of an end portion of the first current collector. 
         [0015]    A fixing protrusion may penetrate the first current collector and may be at a location of the cap assembly to which the first current collector is coupled, the deformation preventer may further include an extension extending toward the fixing protrusion from the body, and the extension may include a through-hole penetrated by the fixing protrusion. 
         [0016]    The extension may have a plate shape and a size corresponding to a lower lateral surface of the first current collector. 
         [0017]    The rechargeable battery may further include a second current collector coupled to the lower part of the cap assembly and may include a first side electrically connected to the second terminal and a second side coupled to the second electrode. 
         [0018]    The rechargeable battery according to some example embodiments of the present invention includes the deformation preventing member. Accordingly, even though the first current collecting member may be loosely combined to the cap assembly, instances of the first current collecting member being deformed may be prevented or reduced by the deformation preventing member. 
         [0019]    Generally, when contact resistance between components increases in the rechargeable battery, high heat may be generated, which may deteriorate performance of the rechargeable battery. However, in the rechargeable battery according to some example embodiments of the present invention, instances of the first current collecting member being twisted may be prevented or reduce, thereby preventing or reducing instances of contact resistance between the first current collecting member and the cap assembly from being increased, thereby manufacturing a high power rechargeable battery. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0020]      FIG. 1  is a perspective view of a rechargeable battery according to an example embodiment of the present invention. 
           [0021]      FIG. 2  is an exploded perspective view of the rechargeable battery according to the example embodiment of the present invention illustrated in  FIG. 1 . 
           [0022]      FIG. 3  is an exploded perspective view showing only a deformation preventing member and a first current collecting member from  FIG. 2 . 
           [0023]      FIG. 4  is an exploded perspective view showing only a cap assembly and a deformation preventing member from a rechargeable battery according to another exemplary embodiment. 
           [0024]      FIG. 5  is a cross-sectional view of the cap assembly assembled taken along the line V-V of  FIG. 4 . 
       
    
    
     DETAILED DESCRIPTION 
       [0025]    Aspects of embodiments of the present invention will be described more fully hereinafter with reference to the accompanying drawings, in which example embodiments of the invention 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 invention. 
         [0026]    The drawings and description are to be regarded as illustrative in nature and not restrictive, and like reference numerals designate like elements throughout the specification. 
         [0027]    Further, in example embodiments, for components having the same configuration, like reference numerals are used and described only in a representative embodiment, and in other example embodiments, only different configurations from the representative embodiment will be described. 
         [0028]    Throughout this specification and the claims that follow, when it is described that an element is “coupled” to another element, the element may be “directly coupled” to the other element or indirectly coupled to the other element through a third element. Further, unless explicitly described to the contrary, the word “comprise” and variations such as “comprises” or “comprising” will be understood to imply the inclusion of stated elements but not the exclusion of any other elements. 
         [0029]      FIG. 1  is a perspective view of a rechargeable battery according to an example embodiment of the present invention,  FIG. 2  is an exploded perspective view of the rechargeable battery according to the example embodiment of the present invention illustrated in  FIG. 1 , and  FIG. 3  is an exploded perspective view showing only a deformation preventing member and a first current collecting member (or first current collector) from  FIG. 2 . For ease of description, in  FIG. 2 , a cap assembly  130  is illustrated such that it is turned upside down. 
         [0030]    Referring to  FIGS. 1 to 3 , the rechargeable battery  100  according to the example embodiment of the present invention includes an electrode assembly  110 , a case  120 , the cap assembly  130 , a first current collecting member (or first current collector)  161 , and a deformation preventing member (or deformation preventer)  170 . 
         [0031]    The rechargeable battery  100  according to some example embodiments will be described such that it has a prismatic shape as a lithium ion rechargeable battery. However, the present invention is not limited thereto, and the present invention may be applicable to various types of batteries such as a lithium polymer battery, a cylindrical battery, etc. 
         [0032]    The electrode assembly  110  includes a first electrode  111  and a second electrode  112 . A separator may be interposed between the first electrode  111  and the second electrode  112 . Herein, the first electrode  111  may be a positive electrode, while the second electrode  112  may be a negative electrode. However, the first electrode  111  is not limited to being the positive electrode and the second electrode  112  is not limited to being the negative electrode, so they can be changed according to a design. 
         [0033]    One side of the case  120  is opened (e.g., the case  120  has an opened side or an opening at a side of the case  120 ). The case  120  accommodates (or encloses) the electrode assembly  110 . For this purpose, the case  120  may have, for example, a cuboid shape. 
         [0034]    According to some embodiments, an opening is formed at a top surface of the case  120 , and the opening may be large enough to receive or accommodate the electrode assembly  110 . That is, the opening may be larger than a cross-sectional area of the electrode assembly  110  to enable the electrode assembly to be inserted through the opening  110 . The case  120  may be, for example, made of a metal such as aluminum, stainless steel, etc. 
         [0035]    The cap assembly  130  includes a cap plate  131 , a first terminal  132 , and a second terminal  133 . 
         [0036]    The cap plate  131  covers the opened part of the case  120 . The cap plate  131  may have, for example, a plate shape that extends in one direction, but it is not limited thereto. 
         [0037]    The first terminal  132  protrudes outside of the cap plate  131 , and is electrically coupled to the first electrode  111 . The first terminal  132  may have, for example, a rectangular plate shape. 
         [0038]    The second terminal  133  protrudes outside of the cap plate  131 , and is electrically coupled to the second electrode  112 . The second terminal  133  may have, for example, a rectangular plate shape. 
         [0039]    The first current collecting member  161  is combined (or coupled) to a lower part of the cap assembly  130 , and has one side electrically coupled to the first terminal  132  and the other side combined (or coupled) to the first electrode  111 . The first terminal  132  may be electrically coupled to the cap assembly  131 . Accordingly, the cap assembly  131  may be charged to have the same polarity as the first electrode  111 . For example, when the first electrode  111  is a positive electrode, the cap assembly  131  may be positively charged. 
         [0040]    The rechargeable battery  100  according to some example embodiments of the present invention may include a second current collecting member  162 . The second current collecting member  162  is combined to the lower part of the cap assembly  130 , and has one side electrically coupled to the second terminal  133  and the other side combined to the second electrode  112 . The second terminal  133  may be charged to have the same polarity as the second electrode  112  by the second current collecting member  162 . For example, when the second electrode  112  is a negative electrode, the second terminal  133  may be positively charged. 
         [0041]    On the other hand, the first terminal  132  described above may be electrically coupled to the first electrode  111  via the first current collecting member  161 . In addition, the second terminal  133  is electrically coupled to the second electrode  112  via the second current collecting member  162 . However, the present invention is not limited thereto, and the first terminal  132  may be electrically coupled to the second electrode  112  and the second terminal  133  may be electrically coupled to the first electrode  111 . 
         [0042]    The deformation preventing member  170  is formed such that it is combined to the lower part of the cap assembly  130  and to accommodate a part of the first current collecting member  161 . The deformation preventing member  170  is formed such that it to support the part of the first current collecting member  161  and to prevent deformation of the first current collecting member  161 . 
         [0043]    A structure in which the deformation preventing member  170  and the cap assembly  130  are combined to prevent the deformation of the first current collecting member  161  will now be described in more detail. 
         [0044]    In the rechargeable battery  100  according to some example embodiments of the present invention, a mounting groove  134  may be formed in the cap assembly  130 . The mounting groove  134  is recessed with a size corresponding to the deformation preventing member  170  such that it partially overlaps the first current collecting member  161 . 
         [0045]    In addition, the deformation preventing member  170  may include a body  171 . The body  171  is accommodated in the mounting groove  134 . A shape of the body  171  may be identical to that of the mounting groove  134 . For example, the body  171  may have a hexahedral shape. In this case, the mounting groove  134  may also have a hexahedral shape. 
         [0046]    A fixing groove  172  may be formed at a lateral side of the body  171 . The fixing groove  172  is recessed to accommodate one end portion of the first current collecting member  161 . For this purpose, the fixing groove  172  may be formed such that it has the same width (e.g., approximately the same width) as the end portion of the first current collecting member  161 . 
         [0047]    The structure of the body  171  and the fixing groove  172  will be described in more detail. A lower part of the body  171  may be partially accommodated in the mounting groove  134 . In addition, the fixing groove  172  may be formed in an upper part of the body  171  that is not accommodated in the mounting groove  134 . 
         [0048]    For example, based on an imaginary horizontal line for separating the body  171  into upper and lower halves, a lower part may be accommodated in the mounting groove  134 , and an upper part may be formed with the fixing groove  172 . However, it is not limited thereto, and the fixing groove  172  may be formed across the upper and lower parts of the body  171 . 
         [0049]    Hereinafter, in the rechargeable battery  100  according to some example embodiments of the present invention, an example variation of the deformation preventing member will be described. 
         [0050]      FIG. 4  is a perspective view of a rechargeable battery according to another example embodiment, and  FIG. 5  is a cross-sectional view of the rechargeable battery illustrated in  FIG. 4  to which the cap assembly is assembled, taken along the like V-V of  FIG. 4 . 
         [0051]    A rechargeable battery  200  according to the current example embodiment will now be described with reference to  FIGS. 4 and 5 . In a portion of a cap assembly  130  to which a first current collecting member  161  is combined, a fixing protrusion  135  penetrating the first current collecting member  161  may be formed. The fixing protrusion  135  may have, for example, a cylindrical shape. 
         [0052]    In addition, the deformation preventing member  270  may further include an extension  273 . The extension  273  is extended toward the fixing protrusion  135  from one lateral side of a body  171 . The extension  273  may have, for example, a plate shape having a size corresponding to a lower lateral surface of a first current collecting member  161 . 
         [0053]    In this case, a through-hole  274  penetrated by the fixing protrusion  135  may be formed in the extension  273 . The fixing protrusion  135  may form the through-hole  274  of the extension  273 , and may be combined to the first current collecting member  161 . 
         [0054]    For example, in order to combine the fixing protrusion  135  and the first current collecting member  161  in a rivet structure, an end portion of the fixing protrusion  135  may be processed by using a separate tool, but it is not limited thereto. 
         [0055]    The structure described above, compared to the deformation preventing member  170  described above (referring to  FIG. 3 ), may have an improved coupling force since a contact area between the first current collecting member  161  and the deformation preventing member  270  increases by the extension  273 . Accordingly, instances of deformation of the first current collecting member  161  can be more reliably prevented or reduced. 
         [0056]    The rechargeable battery  100  according to the example embodiment of the present invention having the structure as described above includes the deformation preventing member  170 . Accordingly, even though the first current collecting member  161  is loosely coupled to the cap assembly  130 , instances of deformation of the first current collecting member  161  can be prevented or reduced by the deformation preventing member  170 . 
         [0057]    Generally, when contact resistance between components increases in the rechargeable battery, high heat may be generated to deteriorate performance of the rechargeable battery. However, in the rechargeable battery  100  according to the example embodiment of the present invention, because instances of the first current collecting member  161  being twisted may be prevented or reduce, such that the contact resistance between the first current collecting member  161  and the cap assembly  130  may not increase, the high power rechargeable battery  100  can be manufactured. 
         [0058]    While this invention has been described in connection with what is presently considered to be practical example embodiments, the drawings and the detailed description of the present invention which are described above are merely illustrative, are just used for the purpose of describing the present invention, and are not used for qualifying the meaning or limiting the scope of the present invention, which is disclosed in the appended claims. Therefore, it will be understood by those skilled in the art that various modifications and other equivalent example embodiments may be made from the present invention. Accordingly, an actual technical protection scope of the present invention is to be defined by the claims, and their equivalents. 
         [0000]    
       
         
               
             
               
               
             
           
               
                   
               
               
                 Description of Some of the Symbols 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                 100:  
                 rechargeable battery 
               
               
                 110:  
                 electrode assembly 
               
               
                 111:  
                 first electrode 
               
               
                 112:  
                 second electrode 
               
               
                 120:  
                 case 
               
               
                 130: 
                 cap assembly 
               
               
                 131: 
                 cap plate 
               
               
                 132: 
                 first terminal 
               
               
                 133: 
                 second terminal 
               
               
                 134:  
                 mounting groove 
               
               
                 135: 
                 fixing protrusion 
               
               
                 161: 
                 first current collecting member 
               
               
                 162:  
                 second current collecting member 
               
               
                 170, 270: 
                 deformation preventing member 
               
               
                 171:  
                 body 
               
               
                 172: 
                 fixing groove 
               
               
                 273: 
                 extension 
               
               
                 274:  
                 through-hole
A rechargeable battery includes: an electrode assembly comprising: a first electrode and a second electrode; a case comprising an opening at a side of the case, the case accommodating the electrode assembly; a cap assembly comprising a cap plate covering the opening of the case, a first terminal protruding out of the cap plate and electrically coupled to a first electrode, and a second terminal protruding out of the cap plate and electrically coupled to a second electrode; a first current collector coupled to a lower part of the cap assembly and having a first side electrically connected to the first terminal and a second side coupled to the first electrode; and a deformation preventer coupled to the lower part of the cap assembly and formed to accommodate a part of the first current collector.