Secondary battery and device including the same
A secondary battery according to one embodiment of the present disclosure includes: a jelly-roll type electrode assembly; a top insulator located at the top of the electrode assembly; and a bottom insulator located at the bottom of the electrode assembly, wherein at least one of the top insulator and the bottom insulator includes a temperature-sensitive polymer that swells in accordance with a temperature rise.
1 . A secondary battery comprising:
a jelly-roll electrode assembly;
a top insulator at a top of the electrode assembly, the top insulator including a main body of insulating fibers and a gel member;
a bottom insulator at a bottom of the electrode assembly;
a cathode tab extending upward from the electrode assembly;
a battery case in which the electrode assembly, the top insulator, and the bottom insulator are housed; and
a cap assembly connected to the top of the battery case,
wherein the top insulator is located between the electrode assembly and the cap assembly,
wherein the cap assembly includes a top cap forming a cathode terminal and a cap plate to which the cathode tab extending upward from the electrode assembly is connected,
wherein the battery case includes a crimping part surrounding the cap assembly,
wherein a gasket is located between the crimping part and the cap assembly,
wherein the main body of the top insulator includes an opening part through which the cathode tab penetrates,
wherein the gel member is disposed between an inner wall of the opening part and the cathode tab,
wherein the gel member of the top insulator includes a temperature-sensitive polymer that swells in accordance with a temperature rise of the temperature-sensitive polymer, and
wherein the temperature-sensitive polymer includes at least one of pNIPAAm (poly(N-isopropylacrylamide)), pDEAM (poly(N,N-diethylacrylamide)), pNEMAM (poly(N-ethylmethacrylamide)), pMVE (poly(methyl vinyl ether)), pEOVE (poly(2-ethoxyethyl vinyl ether)), pNVCa (poly(N-vinylcaprolactam)), pNVIBAM (poly(N-vinylisobutyramide)) and pNVBAM (poly(N-vinyl-n-butyramide).
2 . The secondary battery according to claim 1 , wherein a surface of the main body of the insulating fibers are coated with the temperature-sensitive polymer.
3 . The secondary battery according to claim 2 , wherein the insulating fiber includes at least one of polyethylene, polybutylene, polystyrene, polyethylene terephthalate, polypropylene, glass fiber, natural rubber, and synthetic rubber.
4 . The secondary battery according to claim 1 , wherein an inner wall coating layer containing a binder having self-restoring properties using a reversible covalent bond is disposed on the inner wall of the opening part.
5 . The secondary battery according to claim 4 , wherein the binder includes at least one of a CMC (ceramic matrix composite) material, an arginate material, and a chitosan material.
6 . The secondary battery according to claim 1 , wherein the electrode assembly is fixed between the top insulator and the bottom insulator.
7 . A device comprising at least one secondary battery according to claim 1 .
8 . The secondary battery according to claim 1 , wherein the gel member is configured to swell to fill all of the space of the opening part between the inner wall and the cathode tab.
9 . The secondary battery according to claim 1 , wherein the insulating fibers of the main body are entangled.
10 . The secondary battery according to claim 1 , wherein the insulating fibers of the main body are entangled without having directivity to form a non-woven fabric.