Pouch-type lithium secondary battery and fabrication method thereof

Abstract

A pouch-type lithium secondary battery including a battery unit having a positive electrode plate, a negative electrode plate, and a separator between the positive and negative electrode plates; electrode tabs extending from each of the positive and negative electrode plates of the battery unit, respectively; a case having a space to accommodate the battery unit; a sealing surface along the periphery of the space; and a protection circuit board electrically connected to the electrode tabs, wherein portions of each of the electrode tabs extend outside the case, and are bent in an upright position with respect to a plane of the sealing surface.

1 . A pouch-type lithium secondary battery comprising: 
 a battery unit comprising: 
 a positive electrode plate,  
 a separator, and  
 a negative electrode plate,  
 wherein the separator is disposed between the positive and negative electrode plates;  
   electrode tabs extending from the positive and negative electrode plates of the battery unit;    a case having a space to accommodate the battery unit and a sealing surface formed along the periphery of the space, wherein the case is sealed at the sealing surface by thermal fusion; and    a protection circuit board electrically connected to the electrode tabs,    wherein the protection circuit board is disposed in an approximately upward position with respect to planes of the sealing surfaces of the case.    
   
   
       2 . The pouch-type lithium secondary battery of  claim 1 , wherein the protection circuit board is disposed on the sealing surface.  
   
   
       3 . The pouch-type lithium secondary battery of  claim 1 , wherein the protection circuit board is disposed between an outer wall of the case and the electrode tabs.  
   
   
       4 . The pouch-type lithium secondary battery of  claim 1 , wherein one end of each of the electrode tabs is bent in an upward position with respect to the planes of the sealing surfaces.  
   
   
       5 . The pouch-type lithium secondary battery of  claim 4 , wherein the electrode tabs and a leading edge of the sealing surface are bent a predetermined length in a thickness direction of the case.  
   
   
       6 . The pouch-type lithium secondary battery of  claim 4 , further comprising an insulating tape to provide electrical insulation between the electrode tabs and the sealing surface, wherein the insulating tape is wrapped around the portions of the electrode tabs bent from a leading edge of the sealing surface.  
   
   
       7 . The battery according to  claim 1 , wherein portions of the electrode tabs emerging from the case are folded into a U-shape and have the circuit board positioned on an outer surface of a curve thereof.  
   
   
       8 . The battery according to  claim 1 , wherein portions of the electrode tabs emerging from the case are folded into an S-shape and have the circuit board positioned on an outer surface of a secondary curve thereof.  
   
   
       9 . A battery including a battery unit having a positive electrode plate, a separator, and a negative electrode plate wound together with the separator being disposed between the positive and negative electrode plates and electrode tabs extending from the electrode plates, the battery comprising: 
 a case, having a space with a thickness to accommodate the battery unit, the case including upper and lower portions to be sealed at sealing surfaces formed along the peripheries of the upper and lower portions such that portions of the electrode tabs emerge therefrom; and    a protection circuit board, having a long axis, to be coupled to the electrode tabs and disposed with the long axis being substantially parallel with a direction of the thickness of the case.    
   
   
       10 . The battery according to  claim 9 , wherein the portions of the electrode tabs emerging from the case are folded into a U-shape and have the circuit board positioned on an outer surface of a curve thereof.  
   
   
       11 . The battery according to  claim 9 , wherein the portions of the electrode tabs emerging from the case are folded into an S-shape and have the circuit board positioned on an outer surface of a secondary curve thereof.  
   
   
       12 . The battery according to  claim 9 , wherein the battery is a pouch-type lithium secondary battery.  
   
   
       13 . The battery according to  claim 9 , wherein the battery is a lithium polymer battery.  
   
   
       14 . The battery according to  claim 9 , wherein the upper and lower portions are formed of substantially similar material, and are constructed of multiple layers including an inner coating made of a polymeric insulating layer, a medium layer made of a metal foil to maintain formability, and an outer coating made of a polymeric insulating layer.  
   
   
       15 . A battery including a battery unit having a positive electrode plate, a separator, and a negative electrode plate wound together with the separator being disposed between the positive and negative electrode plates and electrode tabs extending from the electrode plates, the battery comprising: 
 a case, having a space with a thickness to accommodate the battery unit, the case including upper and lower portions to be sealed at planar sealing surfaces formed along the peripheries of the upper and lower portions such that portions of the electrode tabs emerge therefrom; and    a protection circuit board, having a long axis, to be coupled to the electrode tabs and disposed with the long axis being substantially perpendicular with the plane of the sealing surfaces.    
   
   
       16 . The battery according to  claim 15 , wherein the portions of the electrode tabs emerging from the case are folded into a U-shape and have the circuit board positioned on an outer surface of a curve thereof.  
   
   
       17 . The battery according to  claim 15 , wherein the portions of the electrode tabs emerging from the case are folded into an S-shape and have the circuit board positioned on an outer surface of a secondary curve thereof.  
   
   
       18 . The battery according to  claim 15 , wherein the battery is a pouch-type lithium secondary battery.  
   
   
       19 . The battery according to  claim 15 , wherein the battery is a lithium polymer battery.  
   
   
       20 . The battery according to  claim 15 , wherein the upper and lower portions are formed of substantially similar material, and are constructed of multiple layers including an inner coating made of a polymeric insulating layer, a medium layer made of a metal foil to maintain formability, and an outer coating made of a polymeric insulating layer.