Lithium secondary battery including a gasket having an adhesive layer
A cylinder type lithium secondary battery may include an electrode assembly, a cylindrical can configured to retain the electrode assembly, a cap assembly coupled to a top opening of the cylindrical can, an electrolyte disposed in the cylindrical can, and a gasket between the cap assembly and the cylindrical can, the gasket including an adhesive layer having a reaction product of the electrolyte and a material of the gasket.
1. A lithium secondary battery, comprising:
an electrode assembly;
a cylindrical can configured to retain the electrode assembly;
a cap assembly coupled to a top opening of the cylindrical can;
an electrolyte disposed in the cylindrical can; and
a gasket between the cap assembly and the cylindrical can,
wherein the gasket, an entire thickness of which is a reaction product of the electrolyte and oriented polystyrene, contacts bottom and side surfaces of the cap assembly and contacts the cylindrical can, and
wherein the electrolyte includes a carbonate.
2. The lithium secondary battery as claimed in claim 1 , wherein the gasket includes a top portion positioned between the cap assembly and an inner wall of the cylindrical can, a mid portion horizontally extending from a lower end of the top portion, the mid portion having a top surface contacting a bottom edge of the cap assembly seated thereon, and a bottom portion extending from a lower end of the mid portion.
3. The lithium secondary battery as claimed in claim 2 , wherein the top portion, the mid portion, and the bottom portion of the gasket include oriented polystyrene.
4. The lithium secondary battery as claimed in claim 2 , wherein a portion of the gasket contacting the electrolyte includes the bottom portion and a portion of the gasket not contacting the electrolyte includes the top portion.
5. The lithium secondary battery as claimed in claim 2 , wherein the electrolyte contacts the bottom and side surfaces of the cap assembly or contacts the inner wall of the cylindrical can and a beading part.
6. The lithium secondary battery as claimed in claim 1 , wherein the electrolyte contacts a surface of the gasket.
7. The lithium secondary battery as claimed in claim 1 , wherein the gasket has a sealing pressure of about 23.00 kgf/cm 2 or higher.
8. The lithium secondary battery as claimed in claim 7 , wherein the gasket has a sealing pressure of about 29.000 kgf/cm 2 .
9. The lithium secondary battery as claimed in claim 1 , wherein the electrolyte includes dimethyl carbonate, diethyl carbonate, or dipropyl carbonate.
10. The lithium secondary battery as claimed in claim 1 , wherein the gasket is configured to support the cap assembly in the cylindrical can.
11. The lithium secondary battery as claimed in claim 1 , wherein the electrolyte includes methylpropyl carbonate ethylpropyl carbonate, or dipropyl carbonate.
12. The lithium secondary battery as claimed in claim 1 , wherein the electrolyte includes oriented polystyrene.