Pouch type secondary battery and method for manufacturing the same

Abstract

Provided are a pouch type secondary battery capable of preventing corrosion of a metal layer due to exposure of the metal layer to the outside at a distal end of a case thereof, and a method for manufacturing the same.

1 . A pouch type secondary battery comprising:
 a battery assembly including a plurality of electrodes;   cases having an internal space part in which the battery assembly is received;   a sealing part sealed by applying a sealant to a predetermined region of circumferential surfaces of the cases bonded to each other so as to integrate the cases with each other; and   non-bonded parts extended from the circumferential surfaces of the cases forming the sealing part.   
     
     
         2 . The pouch type secondary battery of  claim 1 , wherein the center parts of the non-bonded parts are folded so that end portions of the non-bonded parts are bonded to each other. 
     
     
         3 . The pouch type secondary battery of  claim 2 , wherein the non-bonded parts are sealed by applying the sealant to an outer side of a point at which the non-bonded parts are bonded to each other. 
     
     
         4 . The pouch type secondary battery of  claim 1 , wherein the sealant is a thermoplastic resin. 
     
     
         5 . A method for manufacturing a pouch type secondary battery, the method comprising:
 a primary sealing step of applying a sealant to a predetermined region of circumferential surfaces of cases bonded to each other so as to integrate the cases with each other to perform sealing, thereby forming a sealing part and non-bonded parts;   a folding step of folding the non-bonded parts toward a space therebetween to bond end portions of the non-bonded parts to each other; and   a secondary sealing step of inserting the sealant into a point at which the non-bonded parts are folded to be bonded to each other to perform sealing.   
     
     
         6 . The method of  claim 5 , wherein the folding step includes a primary folding step of vertically bending the center parts of the non-bonded parts toward the space between the non-bonded parts. 
     
     
         7 . The method of  claim 6 , wherein in the primary folding step, a first bending jig of which both sides of one end portion are inclined symmetrically to each other so that a cross section increases is inserted into the space between the non-bonded parts to support inner side surfaces of the non-bonded parts. 
     
     
         8 . The method of  claim 7 , wherein in the primary folding step, a bar shaped pressure jig supports outer side surfaces of the non-bonded parts, and the first bending jig and the pressure jig intersect with each other so as to be in parallel with each other to vertically fold the center parts of the non-bonded parts. 
     
     
         9 . The method of  claim 6 , wherein the folding step includes a secondary folding step of folding the end portions of the non-bonded parts vertically folded in the primary folding step so as to be bonded to each other. 
     
     
         10 . The method of  claim 9 , wherein in the secondary folding step, the first bending jig and the pressure jig intersect with each other so as to be in parallel with each other, and a second bending jig formed in a shape corresponding to one end portion of the first bending jig presses outer side surfaces of the non-bonded parts toward the first bending jig to fold the end portions of the non-bonded parts so as to be bonded to each other.