Secondary battery
A secondary battery includes a cylindrical can; an electrode assembly accommodated in the cylindrical can with an electrolyte; a cap assembly sealing the cylindrical can, a top-end height of the cap assembly being equal to or less than a top-end height of the cylindrical can; and an insulation layer on a surface of the cap assembly that is exposed to the outside of the cylindrical can.
1. A secondary battery comprising:
a cylindrical can;
an electrode assembly accommodated in the cylindrical can;
a cap assembly sealing the cylindrical can, a top-end height of the cap assembly being equal to or less than a top-end height of an electrically-conductive portion of the cylindrical can;
an insulation gasket between the cylindrical can and the cap assembly; and
an insulation layer on a surface of the cap assembly that is exposed to the outside of the cylindrical can.
2. The secondary battery of claim 1 , wherein the insulation layer comprises a polyimide film or a hot melt block.
3. The secondary battery of claim 1 , wherein the cap assembly comprises a cap-up comprising:
a terminal portion;
a bent portion downwardly bent from the terminal portion; and
an extending portion outwardly extending from the bent portion, and
wherein the insulation layer is on the extending portion of the cap-up.
4. The secondary battery of claim 3 , wherein a thickness of the insulation layer is less than a height of the bent portion.
5. The secondary battery of claim 3 , wherein a thickness of the insulation layer is equal to or less than a height of the bent portion.
6. The secondary battery of claim 3 , wherein the cap assembly further comprises a safety plate comprising:
a main body under the cap-up;
a main-body bent portion upwardly extending from a periphery of the main body; and
a main-body extending portion inwardly extending from the main-body bent portion and covering a top surface of the cap-up, and
wherein the insulation layer is on the main-body extending portion of the safety plate.
7. The secondary battery of claim 6 , wherein the insulation layer on the cap-up and the insulation layer on the safety plate are connected to each other.
8. The secondary battery of claim 1 ,
wherein the insulation layer is between the insulation gasket and the cap assembly.
9. The secondary battery of claim 1 , further comprising a lead tab connected to a top end of the cylindrical can.
10. The secondary battery of claim 9 , wherein the insulation layer is between the lead tab and the cap assembly.
11. The secondary battery of claim 1 , wherein an upper-most surface of the cylindrical can is electrically exposed and configured to be electrically connected to an external device.