Abstract:
A method of manufacturing an electrode assembly for a rechargeable battery is disclosed. The method comprises providing a first electrode plate comprising an active portion that is coated with a first active material and an inactive portion extending from an edge of the active portion of the first electrode plate; providing a second electrode plate comprising an active portion that is coated with a second active material and an inactive portion extending from an edge of the active portion of the second electrode plate; providing a separator; winding the first electrode plate, the second electrode plate and the separator, the separator interposed between the first and second electrode plates; and removing parts of the inactive portion of the first electrode plate and the inactive portion of the second electrode plate to form a first plurality of electrode tabs for the first electrode plate and a second plurality of electrode tabs for the second electrode plate.

Description:
RELATED APPLICATIONS 
       [0001]    This application claims the benefit of U.S. Provisional Application. Ser. No. 61/243,908, filed on Sep. 18, 2009, the disclosure of which is incorporated herein by reference in its entirety. 
     
    
     BACKGROUND 
       [0002]    1. Field 
         [0003]    Embodiments of the present invention relate to a method of manufacturing an electrode assembly for a rechargeable battery, and more particularly, to a method of manufacturing an electrode assembly for a rechargeable battery, by which a plurality of tabs is easily formed. 
         [0004]    2. Description of the Related Technology 
         [0005]    Unlike primary batteries that cannot be recharged, rechargeable batteries are chargeable and dischargeable. Rechargeable batteries may be used in a wide range of applications including high-tech electronic devices, such as cellular phones, notebook computers, camcorders, or automobiles. 
         [0006]    Rechargeable batteries can each include an electrode assembly and an electrolyte. The electrolyte can include lithium. The electrode assembly can include a positive electrode plate, a negative electrode plate, and a separator. 
         [0007]    Each of the positive electrode plate and the negative electrode plate of the electrode assembly can include tabs protruding to the exterior. That is, the tabs can protrude outside the electrode assembly and be electrically connected to a container that houses the electrode assembly. The container may be a cylindrical can. 
         [0008]    Recently, each of the positive electrode plate and the negative electrode plate has included a plurality of electrode plates in order to perform charging and discharging with a high-capacity current. However, since the electrode assembly is typically formed by winding the positive electrode plate, the negative electrode plate, and the separator, it is not easy to form a plurality of tabs having a uniform width located at predetermined positions. 
       SUMMARY 
       [0009]    According to an embodiment, a method of manufacturing an electrode assembly for a rechargeable battery comprises providing a first electrode plate comprising an active portion that is coated with a first active material and an inactive portion extending from an edge of the active portion of the first electrode plate; providing a second electrode plate comprising an active portion that is coated with a second active material and an inactive portion extending from an edge of the active portion of the second electrode plate; providing a separator; winding the first electrode plate, the second electrode plate and the separator, the separator interposed between the first and second electrode plates; and removing parts of the inactive portion of the first electrode plate and the inactive portion of the second electrode plate to form a first plurality of electrode tabs for the first electrode plate and a second plurality of electrode tabs for the second electrode plate. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]    The above and other features and advantages will become apparent to those of ordinary skill in the art by describing in detail various embodiments with reference to corresponding drawings, in which: 
           [0011]      FIG. 1  illustrates a schematic view of the structure of a battery pack according to an embodiment; 
           [0012]      FIG. 2  illustrates a flow chart of a method of manufacturing a battery pack according to an embodiment; and 
           [0013]      FIGS. 3 through 8  illustrate schematic views of a method of manufacturing a battery pack according to embodiments. 
       
    
    
       [0014]    These and/or other aspects will become apparent and more readily appreciated from the following description of the embodiments, in conjunction with the accompanying drawings of which: 
         [0015]      FIG. 1  is a schematic perspective view of an electrode assembly for a rechargeable battery, manufactured by using a method according to an embodiment of the present invention; 
         [0016]      FIGS. 2A through 2D  are views to sequentially explain processes of the method described with reference to  FIG. 1 ; 
         [0017]      FIG. 3  is a schematic perspective view of an electrode assembly for a rechargeable battery, manufactured by using a method according to another embodiment of the present invention; 
         [0018]      FIGS. 4A through 4D  are views to sequentially explain processes of the method described with reference to  FIG. 3 ; 
         [0019]      FIG. 5  is a schematic perspective view of an electrode assembly for a rechargeable battery, manufactured by using a method according to another embodiment of the present invention; 
         [0020]      FIGS. 6A through 6D  are views to sequentially explain processes of the method described with reference to  FIG. 5 ; 
         [0021]      FIG. 7  is a schematic perspective view of an electrode assembly for a rechargeable battery, manufactured by using a method according to another embodiment of the present invention; and 
         [0022]      FIGS. 8A through 8D  are views to sequentially explain processes of the method described with reference to  FIG. 7 . 
       DETAILED DESCRIPTION 
       [0023]    With reference to the drawings, the structure and operation of embodiments of the present invention will be described in detail. 
         [0024]      FIG. 1  is a schematic perspective view of an electrode assembly  100  for a rechargeable battery, manufactured by using a method according to an embodiment of the present invention. 
         [0025]    Referring to  FIG. 1 , the electrode assembly  100  may be manufactured by winding in such a manner that the electrode assembly  100  has a cylindrical shape. The electrode assembly  100  can include a separator  105 , a first electrode plate  110 , a second electrode plate  120 , a first electrode tab group  130 , and a second electrode tab group  140 . For example, the electrode assembly  100  may be formed by winding the first electrode plate  110 , the second electrode plate  120 , and the separator  105 , and the separator  105  may be interposed between the first electrode plate  110  and the second electrode plate  120  in such a manner that the first electrode plate  110  is insulated from the second electrode plate  120 . The separator  105  may include an insulating material. 
         [0026]    The first electrode tab group  130  and the second electrode tab group  140  all may be formed on the same side of the electrode assembly  100 . In  FIG. 1 , the first electrode tab group  130  and the second electrode tab group  140  may be formed on a top side of the electrode assembly  100 . 
         [0027]    The first electrode tab group  130  may be connected to the first electrode plate  110 , and the second electrode tab group  140  may be connected to the second electrode plate  120 . However, embodiments of the present invention are not limited thereto. For example, the first electrode tab group  130  and the first electrode plate  110  may be integrally formed, and the second electrode tab group  140  and the second electrode plate  120  may be integrally formed. 
         [0028]    The first electrode plate  110  may be a positive electrode plate, and the second electrode plate  120  may be a negative electrode plate. However, embodiments of the present invention are not limited thereto and the polarity of the respective plates may be altered. To more easily describe embodiments of the present invention, the first electrode plate  110  can be assumed to be a positive electrode plate, and the second electrode plate  120  can be assumed to be a negative electrode plate. 
         [0029]    The first electrode plate  110  may include a first active material portion  111  including a positive electrode active material. The second electrode plate  120  may include a second active material portion (not shown) including a negative electrode active material. Although the first active material portion  111  of the first electrode plate  110  is exposed to the exterior in the embodiment shown in  FIG. 1 , the electrode assembly  100  may also be wound such that the second active material portion of the second electrode plate  120  is exposed outside. 
         [0030]    The first electrode tab group  130  may include a plurality of first electrode tabs  131 , and the second electrode tab group  140  may include a plurality of second electrode tabs  141 . 
         [0031]    The first electrode tabs  131  of the first electrode tab group  130  may have the same width X, and side surfaces of the first electrode tabs  131  may be parallel to each other. 
         [0032]    The second electrode tabs  141  of the second electrode tab group  140  may have the same width X. The width X of the second electrode tabs  141  may be identical to the width X of the first electrode tabs  131 . However, according to another embodiment, the width of the second electrode tabs  141  may also be different from the width of the first electrode tab  131 . Side surfaces of the second electrode tabs  141  may be parallel to each other. 
         [0033]    The cylindrical electrode assembly  100  may be placed in a container such as a cylindrical can and then, an electrolyte is injected into the container and then, the container may be sealed, thereby manufacturing a battery. In this regard, each of the first electrode tab group  130  and the second electrode tab group  140  may include a plurality of electrode tabs. Through the electrode tabs, the battery may be easily charged and discharged with a high-capacity current. 
         [0034]      FIGS. 2A through 2D  are views to sequentially explain processes of the method described with reference to  FIG. 1 . 
         [0035]    Referring to  FIG. 2A , the first electrode plate  110 , the separator  105 , and the second electrode plate  120  can be prepared for stacking. 
         [0036]    The first electrode plate  110  may include a first active material portion  111  that includes a positive electrode active material, and a plurality of first un-coated portions  112  that do not include the positive electrode active material. For example, the first electrode plate  110  may be formed by coating a positive electrode active material on a predetermined portion of a metal thin plate such as an aluminum thin plate. In this regard, a portion that is coated with the positive electrode active material is referred to as the first active material portion  111 , and a portion that is not coated is referred to as the first un-coated portion  112 . The positive electrode active material may include, for example, a mixture including a lithium-based oxide, a binder, a plasticizer, and a conducting agent. 
         [0037]    The first un-coated portions  112  may be aligned on a top side of the first active material portion  111  along the lengthwise direction of the first electrode plate  110 , and have predetermined widths. The first un-coated portions  112  may have widths a 1 , a 2 , and a 3 , respectively, and the first un-coated portions  112  may be spaced apart from each other by distances b 1  and b 2 . In this regard, the widths a 1 , a 2 , and a 3  of the first un-coated portions  112  may be identical to each other, and the distances b 1  and b 2  of the first un-coated portion  112  may also be identical to each other. Accordingly, the first electrode plate  110  may be easily manufactured. Although  FIG. 2A  illustrates three first un-coated portions  112 , the number of the first un-coated portions  112  may vary. 
         [0038]    In the illustrated embodiment, the first un-coated portions  112  and the first electrode plate  110  are integrally formed. However, embodiments of the invention are not limited thereto. For example, the first electrode plate  110  and the first un-coated portions  112  may be separately formed, and then, the first un-coated portions  112  may be connected to the first electrode plate  110 . The connection method may vary; for example, a welding method may be used. 
         [0039]    The second electrode plate  120  can include a second active material portion  121  that further includes a negative electrode active material, and a plurality of second un-coated portions  122  that do not include the negative electrode active material. For example, the second electrode plate  120  may be formed by coating a negative electrode active material on a predetermined portion of a metal thin plate, such as a copper thin plate or a nickel thin plate. In this regard, a portion that is coated with the negative electrode active material may be referred to as the second active material portion  121 , and a portion that is not coated may be referred to as the second un-coated portion  122 . The negative electrode active material may include, for example, a mixture including a carbonaceous material, a binder, a plasticizer, and a conducting agent. 
         [0040]    The second un-coated portions  122  may be aligned on a top side of the second active material portion  121  along the lengthwise direction of the second electrode plate  120 , and may have predetermined widths. The second un-coated portions  122  may include widths c 1 , c 2 , and c 3 , and the second un-coated portions  122  may be spaced apart from each other by distance d 1  and d 2 . In this regard, the widths c 1 , c 2 , and c 3  of the second un-coated portions  122  may be identical to each other, and the distance d 1  and d 2  of the second un-coated portions  122  may be identical to each other. Accordingly, the second electrode plate  120  may be easily manufactured. Although  FIG. 2A  illustrates three second un-coated portions  122 , the number of second un-coated portions  122  may vary. 
         [0041]    In the present embodiment, the second un-coated portions  122  and the second electrode plate  120  may be integrally formed. However, embodiments of the present invention are not limited thereto. For example, the second electrode plate  120  and the second un-coated portions  122  may be separately formed, and then the second un-coated portions  122  may be connected to the second electrode plate  120 . The connection method may vary; for example, a welding method may be used. 
         [0042]    The widths a 1 , a 2 , and a 3  of the first un-coated portions  112  may be identical to the widths c 1 , c 2 , and c 3  of the second un-coated portions  122 , and the distances b 1  and b 2  of the first un-coated portions  112  may be identical to the distances d 1  and d 2  of the second un-coated portions  122 . Thus, in the subsequent process, the first electrode tab group  130  and second electrode tab group  140  having the same widths may be easily manufactured. In this regard, since the first un-coated portions  112  and the second un-coated portions  122  respectively form the first electrode tab group  130  and the second electrode tab group  140  in the subsequent process and the first electrode tab group and the second electrode tab group have different polarity, the first un-coated portions  112  need not be electrically connected to the second un-coated portions  122 . 
         [0043]    Thus, the first un-coated portions  112  and the second un-coated portions  122  are disposed such that the first un-coated portions  112  do not overlap with and are spaced apart from the second un-coated portions  122  as far as possible after the winding. Accordingly, as illustrated in  FIG. 2A , with reference to the lengthwise directions of the first electrode plate  110  and the second electrode plate  120 , positions of the first un-coated portions  112  are different from positions of the second un-coated portions  122 . 
         [0044]    When the first electrode plate  110  and the second electrode plate  120  are stacked and wound, a separator  105  may be used to prevent the first electrode plate  110  and the second electrode plate  120  from being electrically connected to each other. The separator  105  may include any material that has excellent insulating characteristics and is flexible. 
         [0045]    Then, referring to  FIG. 2B , the stack including the first electrode plate  110 , the second electrode plate  120  and the separator  105  can be wound. Referring to  FIG. 2B , the first electrode plate  110 , the second electrode plate  120 , and the separator  105  can be wound while the first electrode plate  110  is exposed outside, thereby exposing the first active material portion  111  of the first electrode plate  110 . However, embodiments of the present invention are not limited thereto. For example, the first electrode plate  110 , the second electrode plate  120 , and the separator  105  may be wound while the second electrode plate  120  is exposed outside, thereby exposing the second active material portion  121  of the second electrode plate  120 . 
         [0046]    The first un-coated portions  112  may be misaligned. That is, side surfaces of the first un-coated portions  112  may not be parallel to each other. Although the first un-coated portions  112  may have the same widths a 1 , a 2 , and a 3 , since the first un-coated portions  112  are spaced apart from each other by distances b 1  and b 2  and the winding diameter changes when the first electrode plate  110  is wound, the first un-coated portions  112  can become misaligned. 
         [0047]    In order to prevent misalignment of the first un-coated portions  112  and to obtain parallel side surfaces of the first un-coated portions  112 , the distances b 1  and b 2  among the first un-coated portions  112  should be adjusted. The distances b 1  and b 2  of the first un-coated portions  112  may be adjusted by considering the thickness of the first electrode plate  110 , the thickness of the second electrode plate  120 , and the thickness of the separator  105 , which requires complicated calculation. In addition, even when the distances b 1  and b 2  among the first un-coated portions  112  are adjusted by considering such factors, the first un-coated portions  112  may also be misaligned according to the shape of the winding structure after winding and the winding density during winding. 
         [0048]    However, according to embodiments of the present invention, positions of the first un-coated portions  112  need not be uniform. Thus, complicated calculations for adjusting of the distances b 1  and b 2  among the first un-coated portions  112  are not required. 
         [0049]    Likewise, side surfaces of the second un-coated portions  122  may not be parallel to each other. Although the widths c 1 , c 2 , and c 3  of the second un-coated portions  122  may be identical to each other, since the distances d 1  and d 2  of the second un-coated portions  122  may also be identical to each other, first un-coated portions  112  can become misaligned while winding the first electrode plate  110 . 
         [0050]      FIG. 2C  is a front view of  FIG. 2B .  FIG. 2C  illustrates the first un-coated portions  112  and does not illustrate the second un-coated portions  122 , to clearly describe the present embodiment. The dashed lines represent left side surfaces of the first un-coated portions  112  which are shielded by a left side surface of the leftmost first un-coated portion  112 . 
         [0051]    Referring to  FIG. 2C , the first un-coated portions  112  are misaligned to each other, and the side surfaces of the first un-coated portions  112  are not parallel to each other and only portions of the respective first un-coated portions  112  corresponding to a predetermined length X overlap with each other. 
         [0052]    Like the first un-coated portions  112 , the second un-coated portions  122  (not shown in  FIG. 2C ) are also misaligned and only portions of the respective second un-coated portions  122  corresponding to the predetermined length X overlap with each other. 
         [0053]    Then, referring to  FIG. 2D , the other portions of the first un-coated portions  112  other than the overlapping portions can be removed. Thus, the first electrode tab group  130  including the first electrode tabs  131  having a width X can be formed. Likewise, the other portions of the second un-coated portions  122  other than the overlapping portions can be removed. Thus, the second electrode tab group  140  including the second electrode tabs  141  having a width X can be formed. 
         [0054]    The process of removing predetermined portions of the first un-coated portions  112  and the second un-coated portions  122  may be a cutting process using a laser. However, embodiments of the present invention are not limited. For example, a blanking process using a mold may also be used. 
         [0055]    Thus, the electrode assembly  100  including the first electrode tab group  130  and the second electrode tab group  140  can be manufactured. 
         [0056]    The electrode assembly  100  can include the first electrode tabs  131  connected to the first electrode plate  110  and the second electrode tabs  141  connected to the second electrode plate  120 . Even when distances among un-coated portions are not controlled when a plurality of tabs are formed, since the other portions of the un-coated portions other than overlapping portions are removed using, for example, a laser apparatus, the first electrode tab group  130  including the first electrode tabs  131  having the same width and parallel side surfaces may be easily formed. The second electrode tab group  140  may also be easily formed likewise. 
         [0057]    In the present embodiment, the first un-coated portions  112  and the first electrode plate  110  may be integrally formed, and thus, the first electrode tab group  130  and the first electrode plate  110  may be integrally formed. Likewise, the second un-coated portions  122  and the second electrode plate  120  may be integrally formed, and thus, the second electrode tab group  140  and the second electrode plate  120  may be integrally formed. Alternatively, as described above, the first un-coated portions  112  and the first electrode plate  110  may be separately formed and then, the first un-coated portions  112  may be connected to the first electrode plate  110 . The second un-coated portions  122  and the second electrode plate  120  may also be separately formed and then, the second un-coated portions  122  may be connected to the second electrode plate  120 . 
         [0058]      FIG. 3  is a schematic perspective view of an electrode assembly  200  for a rechargeable battery, manufactured by using a method according to another embodiment of the present invention. 
         [0059]    Referring to  FIG. 3 , the electrode assembly  200  can be manufactured by winding in such a manner that the electrode assembly  200  has flat side surfaces. The electrode assembly  200  can include a separator  205 , a first electrode plate  210 , a second electrode plate  220 , a first electrode tab group  230 , and a second electrode tab group  240 . 
         [0060]    The electrode assembly  200  according to the present embodiment is the same as the electrode assembly  100  of  FIG. 1 , except for the winding shape of the electrode assembly  200 . Thus, elements of the electrode assembly  200  will not be described in detail. 
         [0061]    The electrode assembly  200  illustrated in  FIG. 3  may be placed in a container such as a rectangular can or a pouch and then, an electrolyte may be injected into the container. The container can then be sealed, thereby manufacturing a battery. In this regard, each of the first electrode tab group  230  and the second electrode tab group  240  can include a plurality of electrode tabs. Through the electrode tabs, the battery may be easily charged and discharged with a high-capacity current. 
         [0062]      FIGS. 4A through 4D  sequentially explain processes of the method described with reference to  FIG. 3 . 
         [0063]    Referring to  FIG. 4A , the first electrode plate  210 , the separator  205 , and the second electrode plate  220  are prepared for stacking. 
         [0064]    The first electrode plate  210 , the separator  205 , and the second electrode plate  220  respectively correspond to the first electrode plate  110 , the separator  105 , and the second electrode plate  120 , which have been described in the previous embodiment and thus, the first electrode plate  210 , the separator  205 , and the second electrode plate  220  will not be described in detail in the present embodiment. Like in the electrode assembly  100  of the previously described embodiment, the first electrode plate  210  and first un-coated portions  212  may be integrally formed. Alternatively, the first un-coated portions  212  may be separately formed and then connected to the first electrode plate  210 . Likewise, the second electrode plate  220  and the second un-coated portions  222  may be integrally formed. Alternatively, the second un-coated portions  222  may be separately formed and then connected to the second electrode plate  220 . 
         [0065]    Referring to  FIG. 4B , the stack including the first electrode plate  210 , the second electrode plate  220 , and the separator  205  may be wound. In the present embodiment, in order to manufacture an electrode assembly for a rectangular or pouch type battery, the first electrode plate  210 , the second electrode plate  220 , and the separator  205  are stacked and then wound such that the stack structure has flat side surfaces. 
         [0066]    Referring to  FIG. 4B , the first electrode plate  210 , the second electrode plate  220 , and the separator  205  may be wound while the first electrode plate  210  is exposed outside, thereby exposing a first active material portion  211  of the first electrode plate  210 . However, embodiments of the present invention are not limited thereto. For example, the first electrode plate  210 , the second electrode plate  220 , and the separator  205  may be wound while the second electrode plate  220  is exposed outside, thereby exposing a second active material portion  221  of the second electrode plate  220 . 
         [0067]    The first un-coated portions  212  may be misaligned. That is, side surfaces of the first un-coated portions  212  may not be parallel to each other. Although the first un-coated portions  212  may have the same widths a 1 , a 2 , and a 3 , since the first un-coated portions  212  may be spaced apart from each other by the same distances b 1  and b 2  and the winding diameter changes when the first electrode plate  210  is wound, the first un-coated portions  212  may be misaligned. 
         [0068]    Likewise, side surfaces of the second un-coated portions  222  may not be parallel to each other. Since the second un-coated portions  222  may have the same widths c 1 , c 2 , and c 3  and the second un-coated portions  222  may be spaced apart from each other by the same distances d 1  and d 2 , the first un-coated portions  212  may be misaligned when the first electrode plate  210  is wound. 
         [0069]      FIG. 4C  is a front view of  FIG. 4B .  FIG. 4C  illustrates the first un-coated portions  212  and do not illustrate the second un-coated portions  222 , to clearly describe the present embodiment. The dashed lines represent left side surfaces of the first un-coated portions  212 , which are shielded by a left side surface of the leftmost first un-coated portion  212 . 
         [0070]    Referring to  FIG. 4C , the first un-coated portions  212  may be misaligned and side surfaces of the first un-coated portions  212  may not be parallel to each other and thus, only portions of the first un-coated portions  212  corresponding to a predetermined length X can overlap with each other. 
         [0071]    Like the first un-coated portions  212 , the second un-coated portions  222 , which are not shown in  FIG. 4C , may also be misaligned and thus, only portions of the second un-coated portions  222  corresponding to the predetermined length X can overlap with each other. 
         [0072]    Referring to  FIG. 4D , the other portions of the first un-coated portions  212  other than the overlapping portions can be removed. Thus, the first electrode tab group  230  including first electrode tabs  231  having the same width X may be formed. Likewise, the other portions of the second un-coated portions  222  other than the overlapping portions can be removed. Thus, the second electrode tab group  240  including second electrode tabs  241  having the same width X may be formed. 
         [0073]    The process of removing predetermined portions of the first un-coated portions  212  and the second un-coated portions  222  may be a cutting process using a laser. However, embodiments of the present invention are not limited. For example, a blanking process using a mold may also be used. 
         [0074]    Thus, the electrode assembly  200  including the first electrode tab group  230  and the second electrode tab group  240  can be manufactured. 
         [0075]    The electrode assembly  200  can include the first electrode tabs  231  connected to the first electrode plate  210  and the second electrode tabs  241  connected to the second electrode plate  220 . Even when distances among un-coated portions are not controlled when a plurality of tabs are formed, since the other portions of the un-coated portions other than overlapping portions are removed using, for example, a laser apparatus, the first electrode tab group  230  including the first electrode tabs  231  having the same width and parallel side surfaces may be easily formed, and the second electrode tab group  240  may also be easily formed likewise. 
         [0076]    In the present illustrated embodiment, the first un-coated portions  212  and the first electrode plate  210  may be integrally formed, and thus, the first electrode tab group  230  and the first electrode plate  210  may be integrally formed. Likewise, the second un-coated portions  222  and the second electrode plate  220  may be integrally formed, and thus, the second electrode tab group  240  and the second electrode plate  220  may be integrally formed. Alternatively, as described above, the first un-coated portions  212  and the first electrode plate  210  may be separately formed and then, the first un-coated portions  212  may be connected to the first electrode plate  210 . The second un-coated portions  222  and the second electrode plate  220  may be separately formed and then, the second un-coated portions  222  may be connected to the second electrode plate  220 . 
         [0077]      FIG. 5  is a schematic perspective view of an electrode assembly  300  for a rechargeable battery, manufactured by using a method according to another embodiment of the present invention. 
         [0078]    Referring to  FIG. 5 , the electrode assembly  300  can be manufactured by winding in such a manner that the electrode assembly  300  has a cylindrical shape. The electrode assembly  300  can include a separator  305 , a first electrode plate  310 , a second electrode plate  320 , a first electrode tab group  330 , and a second electrode tab group  340 . For example, the electrode assembly  300  may be formed by winding the first electrode plate  310 , the second electrode plate  320 , and the separator  305 , and the separator  305  is interposed between the first electrode plate  310  and the second electrode plate  320  in such a manner that the first electrode plate  310  is insulated from the second electrode plate  320 . The separator  305  may include an insulating material. 
         [0079]    The first electrode tab group  330  may be formed on a top side of the electrode assembly  300 , and the second electrode tab group  340  may be formed on a bottom side of the electrode assembly  300 . However, embodiments of the present invention are not limited thereto. For example, the first electrode tab group  330  may be formed on the bottom side of the electrode assembly  300 , and the second electrode tab group  340  may be formed on the to top side of the electrode assembly  300 . That is, the first electrode tab group  330  and the second electrode tab group  340  can be formed on different sides of the electrode assembly  300 . 
         [0080]    The first electrode tab group  330  may be connected to the first electrode plate  310 , and the second electrode tab group  340  may be connected to the second electrode plate  320 . However, embodiments of the present invention are not limited thereto. For example, the first electrode tab group  330  and the first electrode plate  310  may be integrally formed, and the second electrode tab group  340  and the second electrode plate  320  may be integrally formed. 
         [0081]    The first electrode plate  310  may include a first active material portion  311  including a positive electrode active material. The second electrode plate  320  may include a second active material portion (not shown) including a negative electrode active material. Although the first active material portion  311  of the first electrode plate  310  may be exposed outside in  FIG. 5 , the electrode assembly  300  may also be wound such that the second active material portion of the second electrode plate  320  is exposed outside. 
         [0082]    The first electrode tab group  330  may include a plurality of first electrode tabs  331 , and the second electrode tab group  340  may include a plurality of second electrode tabs  341 . 
         [0083]    The first electrode tabs  331  of the first electrode tab group  330  may have the same width X, and side surfaces of the first electrode tabs  331  may be parallel to each other. 
         [0084]    The second electrode tabs  341  of the second electrode tab group  340  may have the same width. The width of the second electrode tabs  341  may be identical to the width X of the first electrode tabs  331 . However, according to another embodiment, the width of the second electrode tabs  341  may also be different from the width of the first electrode tab  331 . Side surfaces of the second electrode tabs  341  may be parallel to each other. 
         [0085]    The cylindrical electrode assembly  300  can be placed in a container such as a cylindrical can and an electrolyte can then be injected into the container. The container can be sealed, thereby manufacturing a battery. In this regard, each of the first electrode tab group  330  and the second electrode tab group  340  can include a plurality of electrode tabs. Through the electrode tabs, the battery may be easily charged and discharged with a high-capacity current. 
         [0086]      FIGS. 6A through 6D  sequentially explain processes of the method described with reference to  FIG. 5 . 
         [0087]    Referring to  FIG. 6A , the first electrode plate  310 , the separator  305 , and the second electrode plate  320  are prepared for stacking. 
         [0088]    The first electrode plate  310  can include a first active material portion  311  which further includes a positive electrode active material and a first un-coated portion  312  that does not include the positive electrode active material. For example, the first electrode plate  310  may be formed by coating a positive electrode active material on a predetermined portion of a metal thin plate such as an aluminum thin plate. In this regard, a portion that is coated with the positive electrode active material is referred to as the first active material portion  311 , and a portion that is not coated is referred to as the first un-coated portion  312 . The positive electrode active material may include, for example, a mixture including a lithium-based oxide, a binder, a plasticizer, and a conducting agent. 
         [0089]    The first un-coated portion  312  may be disposed on a top side of the first active material portion  311 , have a predetermined height, extend in a lengthwise direction of the first electrode plate  310 , and contact a top surface of the first active material portion  311 . 
         [0090]    In the present illustrated embodiment, the first un-coated portion  312  and the first electrode plate  310  may be integrally formed. However, embodiments of the present invention are not limited thereto. For example, the first electrode plate  310  and the first un-coated portion  312  may be separately formed, and then, the first un-coated portion  312  may be connected to the first electrode plate  310 . The connection method may vary; for example, a welding method may be used. 
         [0091]    The second electrode plate  320  can include a second active material portion  321  which further includes a negative electrode active material and a second un-coated portion  322  that does not include the negative electrode active material. For example, the second electrode plate  310  may be formed by coating a negative electrode active material on a predetermined portion of a metal thin plate, such as a copper or nickel thin plate. In this regard, a portion that is coated with the negative electrode active material is referred to as the second active material portion  321 , and a portion that is not coated is referred to as the second un-coated portion  322 . The negative electrode active material may include, for example, a mixture including a carbonaceous material, a binder, a plasticizer, and a conducting agent. 
         [0092]    The second un-coated portion  322  may be disposed on a bottom side of second active material portion  321 , have a predetermined height, extend the lengthwise direction of the second electrode plate  320 , and contact a bottom surface of the second active material portion  321 . 
         [0093]    In the present illustrated embodiment, the second un-coated portion  322  and the second electrode plate  320  may be integrally formed. However, embodiments of the present invention are not limited thereto. For example, the second electrode plate  320  and the second un-coated portion  322  may be separately formed, and then the second un-coated portion  322  may be connected to the second electrode plate  320 . The connection method may vary, for example, a welding method may be used. 
         [0094]    Referring to  FIG. 6A , the first un-coated portion  312  can contact the top surface of the first active material portion  311  and the second un-coated portion  322  can contact the bottom surface of the second active material portion  321 . However, embodiments of the present invention are not limited thereto. For example, the first un-coated portion  312  may contact a bottom surface of the first active material portion  311  and the second un-coated portion  322  may contact a top surface of the second active material portion  321 . 
         [0095]    When the first electrode plate  310  and the second electrode plate  320  are stacked and wound, the separator  305  may be used to prevent the first electrode plate  310  and the second electrode plate  320  from being electrically connected to each other. The separator  305  may include any material that has good insulating characteristics and is flexible. 
         [0096]    Then, referring to  FIG. 6B , the stack including the first electrode plate  310 , the second electrode plate  320  and the separator  305  can be wound. Referring to  FIG. 6B , the first electrode plate  310 , the second electrode plate  320 , and the separator  305  can be wound while the first electrode plate  310  is exposed outside, thereby exposing the first active material portion  311  of the first electrode plate  310 . However, embodiments of the present invention are not limited thereto. For example, the first electrode plate  310 , the second electrode plate  320 , and the separator  305  may be wound while the second electrode plate  320  is exposed outside, thereby exposing the second active material portion  321  of the second electrode plate  320 . 
         [0097]    The first un-coated portion  312  may be exposed on the top side of the first active material portion  311 , and the second un-coated portion  322  may be exposed on the bottom side of the second active material portion  321 . 
         [0098]    Then, the other portion of each of the first un-coated portion  312  and the second un-coated portion  322  other than a predetermined portion may be removed to form electrode tabs. 
         [0099]      FIG. 6C  schematically illustrates a portion of the first un-coated portion  312  that can be removed. Referring to  FIG. 6C , a region A is defined by a dashed line. The region A has a width X. Since the width X corresponds to the width of the electrode tabs in the subsequent process, the width X of the region A may be determined according to a desired width of the electrode tabs. In addition, the width X of the region A may also be determined according to the number of electrode tabs of an electrode tab group. 
         [0100]    Although not illustrated, a portion of the second un-coated portion  322  which can be removed is also marked as described above. In order to obtain the electrode tabs having the same size, the second un-coated portion  322  may also have a region having the same size as the region A of the un-coated portion  312 . 
         [0101]    Then, referring to  FIG. 6D , the region of the first un-coated portion  312  other than the region A may be removed. That is, only in the region A, the first un-coated portion  312  can contact the first active material portion  311 . Thus, the first electrode tab group  330  having the first electrode tabs  331  having the same width X can be formed. 
         [0102]    Likewise, a predetermined portion of the second un-coated portion  322  may be removed to form the second electrode tab group  340 , including the second electrode tabs  341  having the same width. As described above, the portion of the second un-coated portion  322  other than the region having the same size as the region A of the un-coated portion  312  may be removed such that the second electrode tabs  341  have the same shape as the first electrode tab  331 . 
         [0103]    The process of removing predetermined portions of the first un-coated portions  312  and the second un-coated portions  322  may be a cutting process using a laser. However, embodiments of the present invention are not limited. For example, a blanking process using a mold may also be used. 
         [0104]    Thus, the electrode assembly  300  including the first electrode tab group  330  and the second electrode tab group  340  can be manufactured. 
         [0105]    The electrode assembly  300  can include the first electrode tabs  331  connected to the first electrode plate  310 , and the second electrode tabs  341  connected to the second electrode plate  320 . In the present illustrated embodiment, a plurality of tabs may be formed by using an un-coated portion that extends, instead of un-coated portions that are patterned to be spaced apart from each other by predetermined distances. In addition, since the un-coated portion is removed while a predetermined portion of the un-coated portion remains, using, for example, a laser apparatus after winding, electrode tabs having a desired shape may be easily formed. For example, the first electrode tab group  330  having first electrode tabs  331  having the same width and parallel side surfaces may be easily formed, and the second electrode tab group  340  may also be easily formed likewise. 
         [0106]    In the present illustrated embodiment, the first un-coated portion  312  and the first electrode plate  310  may be integrally formed, and thus, the first electrode tab group  330  and the first electrode plate  310  may be integrally formed. Likewise, the second un-coated portion  322  and the second electrode plate  320  may be integrally formed, and thus, the second electrode tab group  340  and the second electrode plate  320  may be integrally formed. Alternatively, as described above, the first un-coated portion  312  and the first electrode plate  310  may be separately formed and then, the first un-coated portion  312  may be connected to the first electrode plate  310 . The second un-coated portion  322  and the second electrode plate  320  may be separately formed, and the second un-coated portion  322  may be connected to the second electrode plate  320 . 
         [0107]      FIG. 7  is a schematic perspective view of an electrode assembly  400  for a rechargeable battery, manufactured by using a method according to another embodiment of the present invention. 
         [0108]    Referring to  FIG. 7 , the electrode assembly  400  may be manufactured by winding in such a manner that the electrode assembly  400  has flat side surfaces. The electrode assembly  400  according to the present embodiment is the same as the electrode assembly  300  of  FIG. 5 , except for the winding shape of the electrode assembly  400 . Thus, elements of the electrode assembly  400  will not be described in detail. 
         [0109]    The electrode assembly  400  illustrated in  FIG. 5  may be placed in a container such as a rectangular can or a pouch, and an electrolyte is injected into the container. The container may then be sealed, thereby manufacturing a battery. In this regard, each of the first electrode tab group  430  and the second electrode tab group  440  can include a plurality of electrode tabs. Through the electrode tabs, the battery may be easily charged and discharged with a high-capacity current. 
         [0110]      FIGS. 8A through 8D  sequentially explain processes of the method described with reference to  FIG. 7 . 
         [0111]    Referring to  FIG. 8A , the first electrode plate  410 , the separator  405 , and the second electrode plate  420  are prepared for stacking. 
         [0112]    The first electrode plate  410 , the separator  405 , and the second electrode plate  420  respectively correspond to the first electrode plate  310 , the separator  305 , and the second electrode plate  320 , which are illustrated in  FIG. 3 . Accordingly, the first electrode plate  410 , the separator  405 , and the second electrode plate  420  will not be described in detail in the present embodiment. 
         [0113]    Like in the electrode assembly  300  according to the previously described embodiment, the first electrode plate  410  and a first un-coated portion  412  may be integrally formed. Alternatively, the first un-coated portion  412  may be separately formed and then connected to the first electrode plate  410 . Likewise, the second electrode plate  420  and a second un-coated portion  422  may be integrally formed. Alternatively, the second un-coated portion  422  may be separately formed, and then connected to the second electrode plate  420 . 
         [0114]    Then, referring to  FIG. 8B , the stack including the first electrode plate  410 , the second electrode plate  420 , and the separator  405  may be wound. Referring to  FIG. 8B , the first electrode plate  410 , the second electrode plate  420 , and the separator  405  may be wound while the first electrode plate  410  is exposed outside, thereby exposing the first active material portion  411  of the first electrode plate  410 . However, embodiments of the present invention are not limited thereto. For example, the first electrode plate  410 , the second electrode plate  420 , and the separator  405  may be wound while the second electrode plate  420  is exposed outside, thereby exposing the second active material portion  421  of the second electrode plate  420 . 
         [0115]    In the present embodiment, in order to manufacture an electrode assembly for a rectangular or pouch type battery, the first electrode plate  410 , the second electrode plate  420 , and the separator  405  can be stacked and then wound such that the stack structure has flat side surfaces. 
         [0116]    The first un-coated portion  412  may be exposed on a top side of the first active material portion  411 , and the second un-coated portion  422  may be exposed on a bottom side of the second active material portion  421 . 
         [0117]    Then, the other region of each of the first un-coated portion  412  and the second un-coated portion  422  other than a predetermined region may be removed, thereby forming electrode tabs. 
         [0118]      FIG. 8C  schematically illustrates a portion of the first un-coated portion  412  which can be removed. Referring to  FIG. 8C , a region A may be defined by a dashed line. The region A has a width X. Since the width X corresponds to the width of the electrode tabs in the subsequent process, the width X of the region A may be determined according to a desired width of the electrode tabs. In addition, the width X of the region A may also be determined according to the number of electrode tabs of an electrode tab group. 
         [0119]    Although not illustrated, a portion of the second un-coated portion  422  which can be removed is also be marked as described above. In order to obtain the electrode tabs having the same size, the second un-coated portion  422  may also have a region having the same size as the region A of the un-coated portion  412 . 
         [0120]    Then, referring to  FIG. 8D , the region of the first un-coated portion  412  other than the region A can be removed. That is, only in the region A, the first un-coated portion  412  contacts the first active material portion  411 . Thus, the first electrode tab group  430  having the first electrode tabs  431  having the same width X can be formed. 
         [0121]    Likewise, a predetermined portion of the second un-coated portion  422  can be removed to form the second electrode tab group  440  including the second electrode tabs  441  having the same width. As described above, the portion of the second un-coated portion  422  other than the region having the same size as the region A of the un-coated portion  412  can be removed such that the second electrode tabs  441  have the same shape as the first electrode tabs  431 . 
         [0122]    Thus, the electrode assembly  400  including the first electrode tab group  430  and the second electrode tab group  440  can be manufactured. 
         [0123]    The electrode assembly  400  may include the first electrode tabs  431  connected to the first electrode plate  410 , and the second electrode tabs  441  connected to the second electrode plate  420 . In the present illustrated embodiment, a plurality of tabs may be formed by using an un-coated portion that extends, instead of un-coated portions that are patterned to be spaced apart from each other by predetermined distances. In addition, since the un-coated portion may be removed while a predetermined portion of the un-coated portion remains, using, for example, a laser apparatus after winding, electrode tabs having a desired shape may be easily formed. For example, the first electrode tab group  430  having first electrode tabs  431  having the same width and parallel side surfaces may be easily formed, and the second electrode tab group  440  may also be easily formed likewise. 
         [0124]    In the present embodiment, the first un-coated portion  412  and the first electrode plate  410  may be integrally formed, and thus, the first electrode tab group  430  and the first electrode plate  410  may be integrally formed. Likewise, the second un-coated portion  422  and the second electrode plate  420  may be integrally formed, and thus, the second electrode tab group  440  and the second electrode plate  420  may be integrally formed. Alternatively, as described above, the first un-coated portion  412  and the first electrode plate  410  may be separately formed and then, the first un-coated portion  412  may be connected to the first electrode plate  410 . The second un-coated portion  422  and the second electrode plate  420  are separately formed and then, the second un-coated portion  422  may be connected to the second electrode plate  420 . 
         [0125]    The embodiments described therein should be considered in a descriptive sense only and not for purposes of limitation. Descriptions of features or aspects within each embodiment should typically be considered as available for other similar features or aspects in other embodiments.