Patent Publication Number: US-2022231321-A1

Title: Rechargeable battery

Description:
TECHNICAL FIELD 
     The present disclosure relates to a rechargeable battery that draws a lead tab connected to an uncoated portion of an electrode to the outside of a case. 
     BACKGROUND ART 
     As technology development and demand for mobile devices increase, a demand for rechargeable batteries as energy sources is rapidly increasing. The rechargeable battery is a battery hat repeatedly performs charging and discharging unlike a primary battery. 
     Small-capacity rechargeable batteries are used in small electronic devices that can be portable, such as a mobile phone, a laptop computer and a camcorder, and large-capacity rechargeable batteries can be used as a power source for driving a motor for a hybrid vehicle and an electric vehicle. 
     For example, the rechargeable battery includes an electrode assembly performing charging and discharging operations, a case accommodating the electrode assembly, and a lead tab drawing the electrode assembly to the outside of the case. The electrode assembly is formed by welding the lead tab to an uncoated portion and winding an electrode and a separator. 
     However, in the electrode assembly, resistance increases at a portion where the uncoated portion and the lead tab are connected to interfere with a high output of the electrode assembly. 
     DISCLOSURE 
     Technical Problem 
     An aspect of the present invention is to provide a rechargeable battery that implements a high output of an electrode assembly by reducing electrical resistance at a connection portion of a uncoated portion and a lead tab. 
     Technical Solution 
     A rechargeable battery according to an embodiment of the present invention includes: an electrode assembly wound by arranging a separator between electrodes; a lead tab connected to the electrode; and a case which accommodates the electrode assembly and of which the lead tab is drawn to the outside, and the lead tab includes a first tab formed with a first width and a first thickness and connected to an uncoated portion of the electrode, and a second tab formed with a second width equal to or less than the first width and a second thickness equal to or more than the first thickness, and connected to the first tab. 
     The second thickness may be larger than the first thickness. 
     The first tab may be connected to the uncoated portion with one surface through a surface contact, and partially protruded to the outside of the uncoated portion, and the second tab may be connected to one surface of the first tab through the surface contact. 
     The second tab may be connected to a side end of the uncoated portion with a side surface in a separation state or a partial contact state. 
     The second tab may be further connected to the side end of the uncoated portion with the side surface through the surface contact. 
     The first tab may be connected to a termination uncoated portion of a first electrode (e.g., anode) and a termination uncoated portion of a second electrode (e.g., cathode) among the electrodes. 
     The first tab may be connected to the leading uncoated portion and the termination uncoated portion of the first electrode (e.g. anode), and connected to the leading uncoated portion and the termination uncoated portion of the second electrode (e.g., cathode) among the electrodes. 
     The first tab may be further connected to an intermediate uncoated portion of the first electrode, and further connected to the intermediate uncoated portion of the second electrode. 
     The first tab may be connected to the leading uncoated portion of the first electrode (e.g., anode) and the termination uncoated portion of the second electrode (e.g., cathode) among the electrodes. 
     The first tab may be connected to the termination uncoated portion of the first electrode (e.g., anode) and the leading uncoated portion of the second electrode (e.g., cathode) among the electrodes. 
     The first tab may be connected to the intermediate uncoated portion of the first electrode (e.g., anode) and the leading uncoated portion and the termination uncoated portion of the second electrode (e.g., cathode) among the electrodes. 
     The first tab may be connected to the leading uncoated portion and the termination uncoated portion of the first electrode (e.g., anode) and may be further connected to the intermediate uncoated portion of the second electrode (e.g., cathode) among the electrodes. 
     Advantageous Effects 
     According to an embodiment of the present invention, since a lead tab is formed by first and second tabs (inner and outer tabs), and a first tab is formed with a first width and a thickness, a second tab is formed with a second thickness equal to or more than the first thickness and a second width equal to or less than the first width, the first tab (inner tab) is connected to an uncoated portion, and the second tab (outer tab) is connected to the first tab, electrical resistance can be reduced at a connection portion of the uncoated portion and the lead tab. That is, a high output of an electrode assembly can be implemented. 
     Further, according to an embodiment, a side surface of the second tab (outer tab) is further connected to a side end of the uncoated portion in a separation state or a partial contact state to facilitate a work process. Further, according to an embodiment, since the side surface of the second tab (outer tab) is further connected to the side end of the uncoated portion through a surface contact, the electrical resistance can be further reduced at the connection portion of the uncoated portion and the lead tab. 
    
    
     
       DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an exploded perspective view illustrating a rechargeable battery according to a first embodiment of the present invention. 
         FIG. 2  is a cross-sectional view taken along line II-II of  FIG. 1 . 
         FIG. 3  is a plan view of both surfaces unfolding and illustrating an electrode applied to an electrode assembly of  FIG. 1 . 
         FIG. 4  is a side view of the electrode illustrated in  FIG. 3 . 
         FIG. 5  is a cross-sectional view taken along line V-V of  FIG. 3 . 
         FIG. 6  illustrates another form of the cross-sectional view taken along line V-V of  FIG. 3 . 
         FIG. 7  is a plan view of both surfaces unfolding and illustrating an electrode applied to an electrode assembly of a rechargeable battery according to a second embodiment of the present invention. 
         FIG. 8  is a plan view of both surfaces unfolding and illustrating an electrode applied to an electrode assembly of a rechargeable battery according to a third embodiment of the present invention. 
         FIG. 9  is a plan view of both surfaces unfolding and illustrating an electrode applied to an electrode assembly of a rechargeable battery according to a fourth embodiment of the present invention. 
         FIG. 10  is a plan view of both surfaces unfolding and illustrating an electrode applied to an electrode assembly of a rechargeable battery according to a fifth embodiment of the present invention. 
         FIG. 11  is a plan view of both surfaces unfolding and illustrating an electrode applied to an electrode assembly of a rechargeable battery according to a sixth embodiment of the present invention. 
         FIG. 12  is a plan view of both surfaces unfolding and illustrating an electrode applied to an electrode assembly of a rechargeable battery according to a seventh embodiment of the present invention. 
     
    
    
     MODE FOR INVENTION 
     The present invention will be described more fully hereinafter with reference to the accompanying drawings, in which exemplary 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 scope of the present invention. The drawings and description are to be regarded as illustrative in nature and not restrictive. Like reference numerals designate like elements throughout the specification. 
       FIG. 1  is an exploded perspective view illustrating a rechargeable battery according to a first embodiment of the present invention and  FIG. 2  is a cross-sectional view taken along line II-II of  FIG. 1 . Referring to  FIGS. 1 and 2 . the rechargeable battery according to the first embodiment includes an electrode assembly  110  charging and discharging current, a lead tab connected to the electrode assembly  110 , and a case (as an example, referred to as a “pouch  120 ”) embedding the electrode assembly  110  and an electrolyte. The lead tab is drawn to the outside of the pouch  120 . 
     The electrode assembly  110  is formed to be accommodated in an internal space of the pouch  120  by arranging and winding electrodes, i.e., a first electrode (for convenience, referred to as an “anode”)  11  and a second electrode (for convenience, referred to as a “cathode”)  12  on both sides with a separator  13  interposed therebetween, and then pressing a wound outer peripheral surface. 
     The lead tab includes a first lead tab (for convenience, referred to as an “anode tab”)  14  and a second lead tab (for convenience, referred to as a “cathode tab”)  15 . The anode tab  14  is electrically connected to the anode  11  and the cathode tab  15  is electrically connected to the cathode  12 . 
       FIG. 3  is a plan view of both surfaces unfolding and illustrating an electrode applied to an electrode assembly of  FIG. 1  and  FIG. 4  is a side view of the electrode illustrated in  FIG. 3 . For convenience, the separator  13  is omitted in  FIGS. 3 and 4 . 
     Referring to  FIGS. 3 and 4 , the anode  11  includes 11 th  and 12 th  coated portions  11   a  and  11   b  formed by applying a positive active material onto both surfaces of a current collector  11   c  of a metal thin plate, and first and second uncoated portions (as an example, leading and termination uncoated portions)  11   d  and  11   e  set as the current collector  11   c  exposed to a leading end and a termination end of the current collector  11   c  because the positive active material is not applied. For example, the current collector  11   c  of the anode  11  may be made of aluminum (Al), and the anode tab  14  connected to the anode  11  may also be made of aluminum (Al). 
     The cathode  12  includes 21 st  and 22 th  coated portions  12   a  and  12   b  formed by applying a negative active material onto both surfaces of a current collector  12   c  of the metal thin plate, and third and fourth uncoated portions (as an example, leading and termination uncoated portions)  12   d  and  12   e  set as the current collector  12   c  exposed to the leading end and the termination end of the current collector  12   c  because the negative active material is not applied. For example, the current collector  12   c  of the cathode  12  may be made of copper (Cu), and the cathode tab  15  connected to the cathode  12  may also be made of copper (Cu). 
     The anode and cathode tabs  14  and  15  includes a first tab (for convenience, referred to as inner tabs  141  and  151 ) and a second tab (for convenience, referred to as outer tabs  142  and  152 ) 
     The inner tabs  141  and  151  are connected to the anode and cathode  11  and  12  by ultrasonic welding or laser welding, and drawn to the outside of the electrode assembly  110  and arranged inside the pouch  120 . 
     The outer tabs  142  and  152  are connected to the inner tabs  141  and  151  by the ultrasonic welding or laser welding outside the electrode assembly  110 , and drawn to the outside of the pouch  120 . That is, the outer tabs  142  and  152  are extended inside and outside the pouch  120 . 
       FIG. 5  is a cross-sectional view taken along line V-V of  FIG. 3 . Referring to  FIGS. 1 to 5 , in the anode and cathode tabs  14  and  15 , the inner tabs  141  and  151  are welded to the termination uncoated portions  11   e  and  12   e  of the anode and cathode  11  and  12  and drawn to the outside of the electrode assembly  110 , and the outer tabs  142  and  152  are welded to the inner tabs  141  and  151  outside the electrode assembly  110 . 
     For convenience, the cathode tabs  15  are not illustrated and the anode tab  14  is illustrated. The inner tabs  141  and  151  are formed with a first width W 1  and a first thickness t 11 , and connected to the termination uncoated portions  11   e  and  12   e  of the anode and cathode  11  and  12 . The inner tabs  141  and  151  are connected to one surface of each of the termination uncoated portions  11   e  and  12   e  through the surface contact and partially protruded outside the termination uncoated portions  11   e  and  12   e.    
     The outer tabs  142  and  152  are formed with a second width W 2  equal to or less than the first width W 1  (W 2 ≤W 1 ) and a second thickness t 2  equal to or more than the first thickness t 1  (t 1 ≤t 2 ), and connected to the inner tabs  141  and  151 . The outer tabs  142  and  152  are formed with a second width W 2  equal to or less than the first width W 1  (W 2 ≤W 1 ) and a second thickness t 2  equal to or more than the first thickness t 1  (t 1 ≤t 2 ), and connected to the inner tabs  141  and  151 . In order to reduce current resistance, the second thickness t 2  may also be larger than the first thickness t 1 ′ (t 1 &lt;t 2 )′ 
     Since the inner tabs  141  and  151  are welded to the termination uncoated portions  11   e  and  12   e  with the first width W 1  which is a sufficient size through the surface contact, the current resistance which flows between the termination uncoated portions  11   e  and  12   e  and the inner tabs  141  and  151  may be reduced. 
     In addition, since the outer tabs  142  and  152  are welded to the inner tabs  141  and  151  with the second thickness t 2  equal to or more than the first thickness t 1  (t 1 ≤t 2 ) through the surface contact, the current resistance which flows between the inner tabs  141  and  151  and the outer tabs  142  and  152  may be reduced. That is, since the outer tabs  142  and  152  increase an outer surface area by the second thickness t 2 , the current resistance is reduced. 
     As such, since the electrical resistance is reduced in the termination uncoated portions  11   e  and  12   e,  connection portions of the inner tabs  141  and  151  and the outer tabs  142  and  152 , and the outer tabs  142  and  152  themselves, a high output of the electrode assembly  110  may be implemented. 
     Meanwhile, the outer tabs  142  and  152  are further connected to side ends of the termination uncoated portions  11   e  and  12   e  with the side surfaces through the surface contact. That is, since the outer tabs  142  and  152  are in surface contact with the inner tabs  141  and  151  which are in surface contact with the termination uncoated portions  11   e  and  12   e  and in surface contact with the side surfaces of the termination uncoated portions  11   e  and  12   e,  contact areas of the outer tabs  142  and  152  and the termination uncoated portions  11   e  and  12   e  are increased. 
     Accordingly, the current resistance which flows between the termination uncoated portions  11   e  and  12   e,  and the inner tabs  141  and  151  and the outer tabs  142  and  152  is further reduced, and further, the high output of the electrode assembly  110  may be further implemented. 
     In this case, the termination uncoated portions  11   e  and  12   e,  and the connection portions of the inner tabs  141  and  151  and the outer tabs  142  and  152  are electrically insulated by the separator  13 . In addition, the termination uncoated portions  11   e  and  12   e  and the inner tabs  141  and  151  are welded to each other, and as a result, a mutual contact may also be firmly formed. 
       FIG. 6  illustrates another form of the cross-sectional view taken along line V-V of  FIG. 3 . When described by referring to  FIGS. 3 and 6 , the outer tabs  142  and  152  may also be further connected to the side ends of the termination uncoated portions  11   e  and  12   e  with the side surfaces in a separation state or a partial contact state. In this case, a connection task process becomes easier than the case where the outer tabs  142  and  152  described above are in surface contact with the side ends of the termination uncoated portions  11   e  and  12   e  with the side surfaces. 
     Although not illustrated, the outer tab may be in surface contact with an opposite surface of the inner tab. In this case, since the outer tab and the side surface of the termination uncoated portion are not in surface contact with each other, a contact area formed between the termination uncoated portion and the outer tab is smaller than the contact area formed in  FIG. 5 . 
     Referring back to  FIGS. 1 and 2 , the pouch  120  accommodates the electrode assembly  110 , and thermally fuses an outer portion to form the rechargeable battery. In this case, the outer tabs  142  and  152  of the anode and cathode tabs  14  and  15  are covered with insulating members  143  and  153 , and drawn to the outside of the pouch  120  through a fused portion. 
     That is, the insulating members  143  and  153  electrically insulate the outer tabs  142  and  152  of the anode and cathode tabs  14  and  15 , and electrically insulates the outer tabs  142  and  152  of the anode and cathode tabs  14  and  15 , and the pouch  120 . 
     The pouch  120  may be formed in a multi-layered sheet structure covering an exterior of the electrode assembly  110 . For example, the pouch  120  includes a polymer sheet  121 , and a nylon sheet  122  and a metal sheet  123 . 
     The polymer sheet  121  forms an inner surface of the pouch  120 , and insulates and thermally fuses, and the nylon sheet  122  forms an outer surface of the pouch  120  and performs a protection action, and the metal sheet  123  provides a mechanical strength to the pouch  120 . 
     The nylon sheet  122  may also be formed by a polyethyleneterephthalate (PET) sheet or a PET-nylon composite sheet. The metal sheet  123  is interposed between the polymer sheet  121  and the nylon sheet  122 , and may also be formed by an aluminum sheet as an example. 
     Further, the pouch  120  includes a first enclosure  201  and a second enclosure  202 . The first and second enclosures  201  and  202  may be formed by the polymer sheet  121 , the nylon sheet  122 , and the metal sheet  123  of the same layer structure. 
     For example, the first enclosure  201  is formed in a concave structure so as to accommodate the electrode assembly  110 . The second enclosure  202  covers the electrode assembly  110  accommodated in the first enclosure  201 , and is formed in parallel so as to be thermally fused to the first enclosure  201  outside the electrode assembly  110 . 
     Although not illustrated, the second enclosure may be integrally connected to the first enclosure in one direction of fourth directions on a plane, and separated in three remaining directions, and as a result, a sealability may be further enhanced in one connected direction. 
     Hereinafter, various embodiments of the present invention will be described. For convenience, a description of the same configuration as the first embodiment and a pre-described embodiments will be omitted and different configurations will be described. 
       FIG. 7  is a plan view of both surfaces unfolding and illustrating an electrode applied to an electrode assembly of a rechargeable battery according to a second embodiment of the present invention. Referring to  FIG. 7 , in the second embodiment, in the anode tabs  14  and  16  of the anode  61 , the inner tabs  141  and  161  are connected to the termination uncoated portion  11   e  and the leading uncoated portion  11   d  of the anode  61  respectively. That is, the anode tabs  14  and  16  form multiple tabs. In addition, in the cathode tabs  15  and  17  of the cathode  62 , the inner tabs  151  and  171  are connected to the termination uncoated portion  12   e  and the leading uncoated portion  21   d  of the cathode  62 , respectively. That is, the cathode tabs  15  and  17  form multiple tabs. 
     As such, two anode tabs  14  and  16  are connected to the termination and leading uncoated portions  11   e  and  11   d  of the anode  61 , respectively, and two cathodes tabs  15  and  17  are connected to the termination and leading uncoated portions  12   e  and  12   d  of the cathode  62 , respectively. Accordingly, since each of the anode tabs  14  and  16  and the cathode tabs  15  and  17  are provided in two, the electrical resistance is further reduced to more effectively implement the high output of the electrode assembly as compared with the first embodiment. 
     That is, as compared with the first embodiment, since the electrical resistance is further reduced in the leading uncoated portions  11   d  and  12   d.  connection portions of the inner tabs  161  and  171  and the outer tabs  162  and  172 , and the outer tabs  162  and  172  themselves, which are further provided, the high output of the electrode assembly may be more effectively implemented. 
       FIG. 8  is a plan view of both surfaces unfolding and illustrating an electrode applied to an electrode assembly of a rechargeable battery according to a third embodiment of the present invention. Referring to  FIG. 8 , in the third embodiment, an anode  71  and a cathode  72  further include intermediate uncoated portions  11   f  and  12   f  as compared with the structures of the anode and cathode  61  and  62  in the second embodiment. 
     In the anode tabs  14 ,  16 , and  18  of the anode  71  the inner tabs  141 ,  161 , and  181  are connected to the termination uncoated portion  11   e,  the leading uncoated portion  11   d,  and the intermediate uncoated portion  11   f  of the anode  71 , respectively. In addition, in the cathode tabs  15 ,  17 , and  19  of the cathode  72 , the inner tabs  151 ,  171 , and  191  are connected to the termination uncoated portion  12   e,  the leading uncoated portion  12   d,  and the intermediate uncoated portion  12   f  of the cathode  72 , respectively. 
     As such, three anode tabs  14 ,  16 , and  18  are connected to the termination, leading, and intermediate uncoated portions  11   e,    11   d,  and  11   f  of the anode  71 , respectively, and three cathodes tabs  15 ,  17 , and  19  are connected to the termination, leading, and intermediate uncoated portions  12   e,    12   d,  and  12   f  of the cathode  72 , respectively. 
     Accordingly, since each of the anode tabs  14 ,  16 , and  18  and the cathode tabs  15 ,  17 , and  19  are provided in three, the electrical resistance is reduced to more effectively implement the high output of the electrode assembly as compared with the second embodiment. 
     That is, as compared with the second embodiment, since the electrical resistance is further reduced in the intermediate uncoated portions  11   f  and  12   f,  connection portions of the inner tabs  181  and  191  and the outer tabs  182  and  192 , and the outer tabs  182  and  192  themselves, the high output of the electrode assembly may be more effectively implemented. 
       FIG. 9  is a plan view of both surfaces unfolding and illustrating an electrode applied to an electrode assembly of a rechargeable battery according to a fourth embodiment of the present invention. Referring to  FIG. 9 , in the fourth embodiment, in the anode tab  16  of the anode  63 , the inner tab  161  is connected to the leading uncoated portion  11   d  of the anode  63 . In addition, in the cathode tab  15  of the cathode  64 , the inner tab  151  is connected to the termination uncoated portion  12   e  of the cathode  64 . 
     As such, one anode tab  16  is connected to the leading uncoated portion  11   d  of the anode  63  and one cathode tab  15  is connected to the termination uncoated portion  12   e  of the cathode  64 . Accordingly, each of the anode tab  16  and the cathode tab  15  are provided in one, and the anode tab  16  and the cathode tab  15  are arranged to cross on the leading end and the termination end, and as a result, as compared with the second embodiment (see  FIG. 7 ), the anode and cathode  16  and  15  are easily arranged, and the electrically resistance such as the first embodiment (see  FIG. 3 ) is reduced to effectively implement the high output of the electrode assembly. 
     That is, the electrical resistance is reduced in the leading uncoated portion  11   d,  the connection portion of the inner tab  161  and the outer tab  162 , the outer tab  162  itself in the anode  63  and in the termination uncoated portion  12   e,  the connection portion of the inner tab  151  and the outer tab  152 , and the outer tab  152  itself in the cathode  64 , and as a result, the high output of the electrode assembly may be effectively implemented as in the first embodiment. 
       FIG. 10  is a plan view of both surfaces unfolding and illustrating an electrode applied to an electrode assembly of a rechargeable battery according to a fifth embodiment of the present invention. Referring to  FIG. 10 , in the fifth embodiment, in the anode tab  14  of the anode  65 , the inner tab  141  is connected to the termination uncoated portion  11   e  of the anode  65 . In addition, in the cathode tab  17  of the cathode  66 , the inner tab  171  is connected to the leading uncoated portion  12   d  of the cathode  66 . 
     As such, one anode tab  14  is connected to the termination uncoated portion  11  e of the anode  65  and one cathode tab  17  is connected to the leading uncoated portion  12   d  of the cathode  66 . Accordingly, each of the anode tab  14  and the cathode tab  17  are provided in one, and the anode tab  14  and the cathode tab  17  are arranged to cross on the termination end and the leading end, and as a result, as compared with the second embodiment (see  FIG. 7 ), the anode tab  14  and the cathode tab  17  are easily arranged, and the electrically resistance such as the first embodiment (see  FIG. 3 ) is reduced to effectively implement the high output of the electrode assembly. 
     That is, the electrical resistance is reduced in the termination uncoated portion  11   e,  the connection portion of the inner tab  141  and the outer tab  142 , the outer tab  142  itself in the anode  65  and in the leading uncoated portion  12   d,  the connection portion of the inner tab  171  and the outer tab  172 . and the outer tab  172  itself in the cathode  66 , and as a result, the high output of the electrode assembly may be effectively implemented as in the first embodiment. 
       FIG. 11  is a plan view of both surfaces unfolding and illustrating an electrode applied to an electrode assembly of a rechargeable battery according to a sixth embodiment of the present invention. Referring to  FIG. 11 , in the fifth embodiment, in the anode tab  18  of the anode  73 , the inner tab  181  is connected to the intermediate uncoated portion  11   f  of the anode  73 . In addition, in the cathode tabs  15  and  17  of the cathode  74 . the inner tabs  151  and  171  are connected to the termination uncoated portion  12   e  and the leading uncoated portion  12   d  of the cathode  74 , respectively. 
     As such, one anode tab  18  is connected to the intermediate uncoated portion  11   f  of the anode  73  and two cathode tabs  15  and  17  are connected to the termination and leading uncoated portions  12   e  and  12   d  of the cathode  74 , respectively. Accordingly, since there is one anode tab  18 , and there are two cathode tabs  15  and  17  the electrical resistance is further reduced in the cathode  74  to more effectively implement the high output of the electrode assembly as compared with the first embodiment. 
     That is, the electrical resistance is reduced in the intermediate uncoated portion  11  f, the connection portion of the inner tab  181  and the outer tab  182 , the outer tab  182  itself in the anode  73  and in the termination and leading uncoated portion  12   e  and  12   d,  the connection portions of the inner tabs  151  and  171  and the outer tabs  152  and  172 , and the outer tabs  152  and  172  themselves in the cathode  74 , and as a result, the high output of the electrode assembly may be effectively implemented 
       FIG. 12  is a plan view of both surfaces unfolding and illustrating an electrode applied to an electrode assembly of a rechargeable battery according to a seventh embodiment of the present invention. Referring to  FIG. 12 , in the seventh embodiment, in the anode tabs  14  and  16  of the anode  75 , the inner tabs  141  and  161  are connected to the termination and leading uncoated portions  11   e  and  11   d  of the anode  75 , respectively. In addition, in the cathode tab  19  of the cathode  76 . the inner tab  191  is connected to the intermediate uncoated portion  12   f  of the cathode  76 . 
     As such, two anode tabs  14  and  16  are connected to the termination and leading uncoated portions  11   e  and  11   d  of the anode  75 , respectively, and one cathodes tab  19  is connected to the intermediate uncoated portions  12   f  of the cathode  76 . Accordingly, since there are two anode tabs  14  and  16 , and there is one cathode tab  19 , the electrical resistance is further reduced in the anode  75  to more effectively implement the high output of the electrode assembly as compared with the first embodiment. 
     That is, the electrical resistance is reduced in the termination and leading uncoated portions  11   e  and  11   d,  the connection portions of the inner tabs  141  and  161  and the outer tabs  142  and  162 , the outer tabs  142  and  162  themselves in the anode  75  and in the intermediate uncoated portion  12   f,  the connection portion of the inner tab  191  and the outer tab  192 , and the outer tab  192  itself in the cathode  76 , and as a result, the high output of the electrode assembly may be effectively implemented. 
     While this invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments. On the contrary, it is intended to cover various modifications and equivalent arrangements included within the scope of the appended claims. 
     
       
         
           
               
             
               
                   
               
               
                 - Description of symbols - 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
            
               
                 10: Electrode assembly 
                 11: First electrode 
               
               
                   
                 (anode) 
               
               
                 11a, 11b: Eleventh, twelfth coating portion 
               
               
                 11c: Current collector 
               
               
                 11d: First uncoated portion (leading uncoated 
               
               
                 portion) 
               
               
                 11e: Second uncoated portion (termination 
               
               
                 uncoated portion) 
               
               
                 11f: Intermediate uncoated portion 
               
               
                 12: Second electrode (cathode) 
               
               
                 12a, 12b: Twenty-first, second coating portion 
               
               
                 12c: Current collector 
               
               
                 12d: Third uncoated portion (leading uncoated 
               
               
                 portion) 
               
               
                 12e: Fourth uncoated portion (termination 
               
               
                 uncoated portion) 
               
               
                 12f: Intermediate uncoated portion 
                 13: Separator 
               
               
                 14, 16, 18: Anode tab (first lead tab) 
               
               
                 15, 17, 19: Cathode tab (second lead tab) 
               
               
                 61, 63, 65, 71, 73, 75: Anode 
                 62, 64, 66, 72, 74, 76: 
               
               
                   
                 Cathode 
               
               
                 120: Case (pouch) 
                 121: Polymer sheet 
               
               
                 122: Nylon sheet 
                 123: Metal sheet 
               
               
                 141, 151, 161, 171, 181, 191: Inner tab (first tab) 
               
               
                 142, 152, 162, 172, 182, 192: Outer tab (second 
               
               
                 tab) 
               
               
                 143, 153: Insulating member 
                 201: First enclosure 
               
               
                 202: Second enclosure 
                 t1: First thickness 
               
               
                 t2: Second thickness 
                 W1: First width 
               
               
                 W2: Second width