Secondary battery
View Patent ↗A secondary battery that can induce an internal short circuit in accordance with a stimulus, for example, excessive internal pressure or temperature, is provided. The secondary battery includes an electrode assembly, a collecting plate electrically connected to the electrode assembly and having a short circuit hole, a short circuit member including a short circuit plate installed in the short circuit hole, a case accommodating the electrode assembly and the collecting plate and having an opening, and a cap assembly including a cap plate sealing the opening of the case. The short circuit plate faces the cap plate.
1. A secondary battery comprising:
an electrode assembly comprising a first electrode having a first polarity and a second electrode having a second polarity different from the first polarity;
a collecting plate electrically connected to the first electrode and having a short circuit hole with an electrically conductive perimeter having the first polarity;
a case accommodating the electrode assembly and the collecting plate and having an opening;
a short circuit member configured to short circuit the secondary battery and comprising a short circuit plate having the first polarity installed in the short circuit hole and including a first side facing a first internal chamber of the case and a second side facing a second internal chamber of the case that is configured to maintain a separate internal pressure from the first internal chamber; and
a cap assembly comprising a cap plate sealing the opening of the case,
wherein the short circuit plate faces the cap plate, and
wherein the short circuit plate and the cap plate are made of a conductive material and configured to have different polarities.
2. The secondary battery of claim 1 , wherein the short circuit plate is spaced apart from the cap plate.
3. The secondary battery of claim 1 , wherein the short circuit plate is configured to contact the cap plate when an internal pressure of the secondary battery exceeds a reference pressure level.
4. The secondary battery of claim 1 , wherein the short circuit plate is configured to contact the cap plate when an internal temperature of the secondary battery exceeds a reference temperature.
5. The secondary battery of claim 1 , wherein the short circuit plate is an invertible plate and comprises:
a downwardly convex round portion; and
an edge portion
extending from an edge of the round portion, and
fixed to a portion of the collecting plate corresponding to a lateral surface of the short circuit hole.
6. The secondary battery of claim 1 , wherein
the short circuit member further comprises a sealing plate between the cap plate and the collecting plate to correspond to a periphery of the short circuit hole, and
the sealing plate has an opening formed at a location corresponding to the short circuit plate.
7. The secondary battery of claim 6 , wherein the sealing plate is made of an insulating material.
8. The secondary battery of claim 6 , further comprising a lower insulation member between the collecting plate and the cap plate and covering the collecting plate, wherein the lower insulation member has an exposing hole formed at a location corresponding to the short circuit plate.
9. The secondary battery of claim 8 , wherein top surfaces of the lower insulation member and the sealing plate are coplanar.
10. The secondary battery of claim 1 , wherein the collecting plate comprises:
a connecting portion between an upper portion of the electrode assembly and a lower portion of the cap assembly and having the short circuit hole; and
an extending portion
extending substantially perpendicularly from an end of the connecting portion, and
electrically connected to the first electrode.
11. The secondary battery of claim 10 , wherein the connecting portion further has a fuse hole formed between the short circuit hole and the extending portion.