Separator for lithium secondary battery and lithium secondary battery comprising the same
Disclosed is a separator for a lithium secondary battery and a lithium secondary battery comprising the same. The separator may include a thermoplastic polyolefin-based polymer porous sheet and an aramid-based non-woven fabric sheet stacked on at least one surface of the polyolefin-based polymer porous sheet, wherein the polyolefin-based polymer sheet and the aramid-based non-woven fabric sheet are adhered with an adhesive, and the adhesive loses an adhesive performance at 80° C. or more to separate the two sheets. The separator has a shut-down function and excellent high-temperature shape stability.
1. A separator for a lithium secondary battery, the separator comprising:
a thermoplastic polyolefin-based polymer porous sheet; and
an aramid-based non-woven fabric sheet stacked on both surfaces of the polyolefin-based polymer porous sheet,
wherein the polyolefin-based polymer sheet and the aramid-based non-woven fabric sheet are adhered with an adhesive, the adhesive is applied onto the edges of both surfaces of the polyolefin-based polymer porous sheet, and the adhesive loses an adhesive performance at 80° C. or more to separate the two sheets.
2. The separator for a lithium secondary battery according to claim 1 , wherein the polyolefin-based polymer sheet is a sheet of at least one selected from the group consisting of polyethylene, polypropylene, polybutene, polymethylpentene, and copolymers thereof.
3. The separator for a lithium secondary battery according to claim 1 , wherein the polyolefin-based polymer sheet has a melting point of 110 to 160° C.
4. The separator for a lithium secondary battery according to claim 1 , wherein the polyolefin-based polymer sheet has a porosity of 30 to 80%.
5. The separator for a lithium secondary battery according to claim 1 , wherein the polyolefin-based polymer sheet has an air permeability of 100 to 400 sec/100 ml.
6. The separator for a lithium secondary battery according to claim 1 , wherein the aramid-based non-woven fabric sheet has a porosity of 40 to 70%.
7. The separator for a lithium secondary battery according to claim 1 , wherein the aramid-based non-woven fabric sheet has an air permeability of 1 to 20 sec/100 ml.
8. The separator for a lithium secondary battery according to claim 1 , wherein the separator has a porosity of 40 to 60%.
9. The separator for a lithium secondary battery according to claim 1 , wherein the separator has an air permeability of 150 to 300 sec/100 ml.
10. The separator for a lithium secondary battery according to claim 1 , wherein the separator has a thickness of 10 to 50 μm.
11. A lithium secondary battery comprising:
a cathode;
an anode; and
a separator interposed between the cathode and the anode, wherein the separator is defined in claim 1 .