Electrode assembly and rechargeable battery using the same
View Patent ↗A rechargeable battery includes an electrode assembly including a positive electrode including a positive current collector, a positive active material on the positive current collector in a positive coating region, and a positive uncoated region in which the positive active material is not on the positive current collector at a first side of the electrode assembly; a negative electrode including a negative current collector, a negative active material on the negative current collector in a negative coating region, a first negative uncoated region in which the negative active material is not on the negative current collector at the first side of the electrode assembly, and a second negative uncoated region in which the negative active material is not on the negative current collector at a second side of the electrode assembly opposite the first side; and a separator between the positive electrode and the negative electrode.
1. A rechargeable battery comprising:
an electrode assembly comprising:
a positive electrode comprising a positive current collector, a positive active material on the positive current collector in a positive coating region, and a positive uncoated region in which the positive active material is not on the positive current collector at a first side of the electrode assembly;
a negative electrode comprising a negative current collector, a negative active material on the negative current collector in a negative coating region, a first negative uncoated region in which the negative active material is not on the negative current collector at the first side of the electrode assembly, and a second negative uncoated region in which the negative active material is not on the negative current collector at a second side of the electrode assembly opposite the first side; and
a separator between the positive electrode and the negative electrode;
a case containing the electrode assembly and having an opening at an end thereof for receiving the electrode assembly;
a cap assembly comprising a cap plate sealing the opening; and
a terminal electrically connected to the positive electrode or the negative electrode and protruding outside the case;
wherein the separator protrudes farther at the first side than the first negative uncoated region, and the positive uncoated region protrudes farther at the first side than the separator; and
wherein the negative coating region protrudes farther at the first side than the positive coating region.
2. The rechargeable battery of claim 1 , wherein the first negative uncoated region has a width that is less than a width of the second negative uncoated region.
3. The rechargeable battery of claim 1 , wherein the following condition is satisfied:
D1≦SQ≦D2,
where D 1 is a lateral distance from the first negative uncoated region to an end of the separator at the first side, D 2 is a lateral distance from the negative coating region to the end of the separator, and SQ is a lateral distance by which the end of the separator is thermally contracted at a reference temperature.
4. The rechargeable battery of claim 1 , wherein a lateral distance from the first negative uncoated region to an end of the separator at the first side is about 0.5 mm to about 10 mm.
5. The rechargeable battery of claim 1 , wherein a distance between the positive uncoated region and the first negative uncoated region is about 0.05 mm to about 0.5 mm.
6. The rechargeable battery of claim 1 , wherein the following condition is satisfied:
D3≦D2≦30 mm,
where D 2 is a lateral distance from the negative coating region to an end of the separator at the first side, and D 3 is a distance between the positive uncoated region and the first negative uncoated region.
7. The rechargeable battery of claim 1 , wherein the following condition is satisfied:
(2 *D 1 /SW 1)*100(%)≦ SR 1(%)≦(2 *D 2 /SW 1)*100(%),
where D 1 is a lateral distance from the first negative uncoated region to an end of the separator at the first side, D2 is a lateral distance from the negative coating region to the end of the separator, SW 1 is a width of the separator before the separator is thermally contracted, and SR 1 is a percentage of contraction when the separator is thermally contracted at a reference temperature.
8. The rechargeable battery of claim 1 , wherein the separator comprises a polymer membrane and a ceramic embedded therein.
9. The rechargeable battery of claim 1 , wherein the separator comprises a porous member and ceramic layer thereon.
10. The rechargeable battery of claim 1 , wherein the negative electrode comprises a ceramic layer on the negative active material.
11. The rechargeable battery of claim 1 , wherein the first and second sides of the electrode assembly are at opposite ends of the electrode assembly along a direction of a winding axis of the electrode assembly.
12. A rechargeable battery comprising:
an electrode assembly comprising:
a first electrode comprising a first current collector, a first active material on the first current collector in a first coating region, and a first uncoated region in which the first active material is not on the first current collector at one side of the electrode assembly;
a second electrode comprising a second current collector, a second active material on the second current collector in a second coating region, a second uncoated region in which the second active material is not on the second current collector at the one side of the electrode assembly, the second uncoated region protruding farther at the one side than the first uncoated region; and
a separator between the first electrode and the second electrode;
a case containing the electrode assembly; and
a terminal electrically connected to the first electrode or the second electrode and protruding outside the case;
wherein the separator protrudes farther at the one side than the first uncoated region;
wherein the second uncoated region protrudes farther at the one side than the separator; and
wherein the first coating region protrudes farther at the one side than the second coating region.
13. The rechargeable battery of claim 12 , wherein the following condition is satisfied:
D1≦SQ≦D2,
where D 1 is a lateral distance from the first uncoated region to an end of the separator at the one side, D 2 is a lateral distance from the first coating region to the end of the separator, and SQ is a lateral distance by which the end of the separator is thermally contracted at a reference temperature.
14. The rechargeable battery of claim 12 , wherein a lateral distance from the first uncoated region to an end of the separator at the one side is about 0.5 mm to about 10 mm.
15. The rechargeable battery of claim 12 , wherein a distance between the first uncoated region and the second uncoated region is about 0.05 mm to about 0.5 mm.
16. The rechargeable battery of claim 12 , wherein the following condition is satisfied:
D3≦D2≦30 mm,
where D 2 is a lateral distance from the first coating region to an end of the separator at the one side, and D 3 is a distance between the second uncoated region and the first uncoated region.
17. The rechargeable battery of claim 12 , wherein the following condition is satisfied:
(2 *D 1 /SW 1)*100(%)≦ SR 1(%)≦(2 *D 2 /SW 1)*100(%),
where D 1 is a lateral distance from the first uncoated region to an end of the separator at the one side, D 2 is a lateral distance from the first coating region to the end of the separator, SW 1 is a width of the separator before the separator is thermally contracted, and SR 1 is a percentage of contraction when the separator is thermally contracted at a reference temperature.
18. The rechargeable battery of claim 12 , wherein the separator comprises a polymer membrane and a ceramic embedded therein.
19. The rechargeable battery of claim 12 , wherein the separator comprises a porous member and a ceramic layer thereon.
20. The rechargeable battery of claim 12 , wherein the first electrode comprises a ceramic layer on the first active material.