Cap assembly for secondary battery and secondary battery including the same

Patent metadata

Field	Value
Publication number	US-10333133-B2
Application number	US-201715398360-A
Country	US
Kind code	B2
Filing date	Jan 4, 2017
Priority date	Jan 20, 2016
Publication date	Jun 25, 2019
Grant date	Jun 25, 2019

Abstract

A cap assembly for a secondary battery includes: a cap plate; a current interrupt device (CID); a middle plate; and an insulator. The CID includes: a vent plate under the cap plate and including a vent portion protruding downward; and a sub-plate under the vent plate and connected to the vent portion. The middle plate is between the vent plate and the sub-plate and is electrically connected to the vent plate via the sub-plate. The insulator is between the vent plate and the middle plate, and the insulator includes a crosslinked polymer.

First claim

What is claimed is:

1. A cap assembly for a secondary battery, the cap assembly comprising:
a cap plate;
a current interrupt device (CID) comprising:
a vent plate under the cap plate and comprising a vent portion protruding downward, the vent plate being configured to deform in response to an increase in an internal pressure of the secondary battery; and
a sub-plate under the vent plate and connected to the vent portion;

a middle plate between the vent plate and the sub-plate and electrically connected to the vent plate via the sub-plate;
an insulator between the vent plate and the middle plate, the insulator comprising a crosslinked polypropylene (PP) resin or a crosslinked polyethylene (PE) resin and having a circular ring shape having a central opening; and
an anti-deformation rib extending along an outer periphery of the circular ring shape of the insulator and protruding downward.

2. The cap assembly of claim 1 , wherein the anti-deformation rib has a downwardly-decreasing thickness.

3. The cap assembly of claim 2 , wherein the anti-deformation rib has an inner side and an outer side, and the outer side of the anti-deformation rib is tapered.

4. The cap assembly of claim 1 , wherein the insulator comprises a plurality of protrusions protruding from an inner side of the circular ring shape of the insulator toward a center of the insulator along an inner periphery of the inner side.

5. The cap assembly of claim 4 , wherein the vent plate has an S-shaped bent structure comprising a lower bent portion and an upper bent portion, and the vent plate is interference fitted into the circular ring shape of the insulator, and
wherein the plurality of protrusions engage an upper portion of the lower bent portion to couple the vent plate to the insulator.

6. The cap assembly of claim 1 , wherein the middle plate and the insulator each have a penetration opening in center regions thereof, and
wherein the vent portion is directly connected to a center region of the sub-plate through the penetration opening of the insulator and the penetration opening of the middle plate.

7. A secondary battery comprising:
a can having an opening;
an electrode assembly in the can; and
a cap assembly sealing the opening of the can and electrically connected to the electrode assembly, the cap assembly comprising:
a cap plate;
a current interrupt device (CID) comprising:
a vent plate under the cap plate and comprising a vent portion protruding toward the electrode assembly, the vent plate being configured to deform in response to an increase in an internal pressure of the can; and
a sub-plate under the vent plate and connected to the vent portion;

a middle plate between the vent plate and the sub-plate and electrically connected to the vent plate via the sub-plate; and

an insulator between the vent plate and the middle plate, the insulator comprising a crosslinked polypropylene (PP) resin or a crosslinked polyethylene (PE) resin and having a circular ring shape having a central opening; and
an anti-deformation rib extending along an outer periphery of the circular ring shape of the insulator and protruding downward.

Assignees

• Samsung Sdi Co Ltd

Inventors

• Park Gun Gue
• Bak Hyo Rim

Classifications

• H01M50/169

  by welding, brazing or soldering · CPC title

• H01M50/593

  Spacers; Insulating plates · CPC title

• H01M2/046

  Electricity · mapped topic

• H01M2200/20

  Pressure-sensitive devices · CPC title

• H01M2/345 Primary

  Electricity · mapped topic