Battery cell of asymmetric structure and battery pack employed with the same
View Patent ↗Disclosed herein is a battery cell configured to have a structure in which an electrode assembly including a separator disposed between a cathode and an anode is mounted in a battery case, wherein an asymmetric structure with respect to a central axis crossing the electrode assembly in plane is formed at a portion of at least one side of the electrode assembly constituting the outer circumference of the electrode assembly.
1. A method of manufacturing a battery cell, the method comprising the steps of:
cutting a laminate sheet comprising a metal layer and a resin layer into an unfolded battery case form to prepare a battery case sheet;
folding the battery case sheet with respect to a symmetrical axis to form a folded portion;
applying external force to the folded portion from an inside to an outside of the folded portion to form a curved portion corresponding to a deflection part of one side of an asymmetric electrode assembly;
applying external force to an inside of the battery case sheet to form a receiving part;
placing the asymmetric electrode assembly having the deflection part at one side thereof in the receiving part;
connecting electrode terminals with the electrode assembly, the electrode terminals being located opposite the folded portion; and
hermetically sealing the battery case sheet, including sealing the area at the location of the electrode terminals, thereafter purging gas from the battery case at an unsealed location, and thereafter sealing the unsealed location.
2. The method according to claim 1 , wherein the unfolded battery case form corresponds to a shape of the battery case.
3. The method according to claim 1 , wherein the external forces are applied using a deep drawing method.
4. The method according to claim 1 , wherein the step of hermetically sealing is achieved using a thermal welding method.
5. The method according to claim 1 , wherein at least a portion of the curved portion of the battery case is not thermally welded.
6. The method according to claim 1 , wherein the asymmetric part is located at one of the sides of the battery case formed using the deep drawing method.
7. The method according to claim 1 , further comprising a step of impregnating the electrode assembly with an electrolyte.