Multilayer separator and device using the same

1. A multilayer separator, comprising:

at least one first porous substrate; and

at least one second porous substrate,

wherein the peeling strength between the first porous substrate and the second porous substrate is in a range of 2 N/m to 30 N/m, and the first porous substrate has an obturator temperature of lower than 135° C.; and

wherein the multilayer separator has an air permeability of 50 s/100 cc to 1000 s/100 cc, and wherein the air permeability of the first porous substrate is 30% to 80% of the air permeability of the multilayer separator, and the air permeability of the second porous substrate is 20% to 70% of the air permeability of the multilayer separator.

2. The multilayer separator according to claim 1 , wherein the second porous substrate has a broken membrane temperature of higher than 145° C.

3. The multilayer separator according to claim 1 , wherein the multilayer separator has a thickness of 5 μm to 30 μm, and wherein the thickness of the first porous substrate is 10% to 70% of the thickness of the multilayer separator, and the thickness of the second porous substrate is 30% to 90% of the thickness of the multilayer separator.

4. The multilayer separator according to claim 1 , wherein the multilayer separator has an obturator temperature of lower than 135° C. and broken membrane temperature of higher than 145° C.

5. The multilayer separator according to claim 1 , wherein the material of the first porous substrate comprises at least one or more of: high-density polyethylene, low-density polyethylene, linear low-density polyethylene, medium-density polyethylene, ultrahigh-molecular-weight polyethylene and polyethylene wax with an average molecular weight of 1000 g/mol to 20000 g/mol.

6. The multilayer separator according to claim 1 , wherein the material of the second porous substrate comprises at least one or more of: ultrahigh-molecular-weight polyethylene, high-density polyethylene, polypropylene, polyethylene terephthalate, polyphenylene sulfide, cellulose, polyimide, polystyrene, poly(4-methyl-l-pentene), polymethyl methacrylate, polyvinylidene fluoride, polyvinylidene fluoride-hexafluoropropylene, polytetrafluoroethylene and polysulfone.

7. The multilayer separator according to claim 1 , wherein the multilayer separator further comprises at least one coating on one side or two sides of the multilayer separator, and the coating comprises one or two of inorganic particles and polymers.

8. An electrochemical device, comprising:

a cathode;

an anode; and

a multilayer separator located between the cathode and the anode, wherein the multilayer separator comprises:

at least one first porous substrate; and

at least one second porous substrate,

wherein the peeling strength between the first porous substrate and the second porous substrate is in a range of 2 N/m to 30 N/m, and the first porous substrate has an obturator temperature of lower than 135° C.; and

wherein the multilayer separator has an air permeability of 50 s/100 cc to 1000 s/100 cc, and wherein the air permeability of the first porous substrate is 30% to 80% of the air permeability of the multilayer separator, and the air permeability of the second porous substrate is 20% to 70% of the air permeability of the multilayer separator.

9. The electrochemical device according to claim 8 , wherein the second porous substrate has a broken membrane temperature of higher than 145° C.

10. The electrochemical device according to claim 8 , wherein the multilayer separator has a thickness of 5 μm to 30 μm, and wherein the thickness of the first porous substrate is 10% to 70% of the thickness of the multilayer separator, and the thickness of the second porous substrate is 30% to 90% of the thickness of the multilayer separator.

11. The electrochemical device according to claim 8 , wherein the multilayer separator has an obturator temperature of lower than 135° C. and broken membrane temperature of higher than 145° C.

12. The electrochemical device according to claim 8 , wherein the material of the first porous substrate comprises at least one or more of: high-density polyethylene, low-density polyethylene, linear low-density polyethylene, medium-density polyethylene, ultrahigh-molecular-weight polyethylene and polyethylene wax with an average molecular weight of 1000 g/mol to 20000 g/mol.

13. The electrochemical device according to claim 8 , wherein the material of the second porous substrate comprises at least one or more of: ultrahigh-molecular-weight polyethylene, high-density polyethylene, polypropylene, polyethylene terephthalate, polyphenylene sulfide, cellulose, polyimide, polystyrene, poly(4-methyl-l-pentene), polymethyl methacrylate, polyvinylidene fluoride, polyvinylidene fluoride-hexafluoropropylene, polytetrafluoroethylene and polysulfone.

14. The electrochemical device according to claim 8 , wherein the multilayer separator further comprises at least one coating on one side or two sides of the multilayer separator, and the coating comprises one or two of inorganic particles and polymers.

15. An electronic device, comprising an electrochemical device that includes:

a cathode;

an anode; and

a multilayer separator located between the cathode and the anode, wherein the multilayer separator comprises:

at least one first porous substrate; and

at least one second porous substrate,

wherein the peeling strength between the first porous substrate and the second porous substrate is in a range of 2 N/m to 30 N/m, and the first porous substrate has an obturator temperature of lower than 135° C.; and

wherein the multilayer separator has an air permeability of 50 s/100 cc to 1000 s/100 cc, and wherein the air permeability of the first porous substrate is 30% to 80% of the air permeability of the multilayer separator, and the air permeability of the second porous substrate is 20% to 70% of the air permeability of the multilayer separator.