Separator for lithium secondary battery, method for manufacturing same, and lithium secondary battery including same

1. A separator for a lithium rechargeable battery, comprising

a porous substrate and heat resistance porous layer disposed on at least one surface of the porous substrate,

wherein the heat resistance porous layer includes sulfonic acid group-containing polysulfone.

2. The separator of claim 1 , wherein the sulfonic acid group-containing polysulfone includes a unit represented by Chemical Formula 1:

wherein, in Chemical Formula 1,

a and b are independently numbers of 0 to 4, the sum of a and b is greater than or equal to 1.

3. The separator of claim 1 , wherein the sulfonic acid group-containing polysulfone is sulfonic acid group-containing polyarylene ethersulfone.

4. The separator of claim 1 , wherein the sulfonic acid group-containing polysulfone includes a unit represented by Chemical Formula 2:

wherein, in Chemical Formula 2,

a and b are independently numbers of 0 to 4, the sum of a and b is greater than or equal to 1, and

R 1 is a divalent functional group including a C3 to C30 aromatic ring, wherein the aromatic ring is present alone or two or more aromatic rings are linked by a single bond, —O—, —S—, —C(═O)—, —CH(OH)—, —S(═O) 2 —, —NH—, —Si(CH 3 ) 2 —, —(CH 2 ) p — (wherein 1≤p≤10), —(CF 2 ) q — (wherein 1≤q≤10), —C(CH 3 ) 2 —, —C(CF 3 ) 2 —, or —C(═O)NH.

5. The separator of claim 1 , wherein the sulfonic acid group-containing polysulfone includes a unit represented by Chemical Formula 3:

[Chemical Formula 3]

wherein, in Chemical Formula 3,

a and b are independently numbers of 0 to 4, the sum of a and b is greater than or equal to 1,

R 1 and R 2 are the same or different and are independently a divalent functional group including a C3 to C30 aromatic ring, wherein the aromatic ring is present alone or two or more aromatic rings are linked by a single bond, —O—, —S—, —C(═O)—, —CH(OH)—, —S(═O) 2 —, —NH—, —Si(CH 3 ) 2 —, —(CH 2 ) p — (wherein 1≤q≤10), —(CF 2 ) q — (wherein 1≤q≤10), —C(CH 3 ) 2 —, —C(CF 3 ) 2 —, or —C(═O)NH, and

0<x≤1.

6. The separator of claim 1 , wherein a weight average molecular weight of the sulfonic acid group-containing polysulfone ranges from about 20,000 g/mol to about 200,000 g/mol.

7. The separator of claim 1 , wherein the heat resistance porous layer further includes a filler.

8. The separator of claim 7 , wherein the filler includes Al 2 O 3 , SiO 2 , TiO 2 , SnO 2 , CeO 2 , MgO, NiO, CaO, GaO, ZnO, ZrO 2 , Y 2 O 3 , SrTiO 3 , BaTiO 3 , Mg(OH) 2 , boehmite, or a combination thereof.

9. The separator of claim 7 , wherein the sulfonic acid group-containing polysulfone is included in an amount of about 0.1% to about 40% and the filler is included in an amount of about 60% to about 99.9% based on the total weight of the sulfonic acid group-containing polysulfone and the filler.

10. A method of manufacturing a separator for a lithium rechargeable battery, comprising

dispersing a sulfonic acid group-containing polysulfone in a low-boiling-point solvent into a nano-size to prepare nano dispersion liquid,

applying the nano dispersion liquid on at least one surface of a porous substrate, and

obtaining a separator including a heat resistance porous layer including sulfonic acid group-containing polysulfone on at least one surface of the porous substrate.

11. The method of claim 10 , wherein the dispersing of the sulfonic acid group-containing polysulfone in a low-boiling-point solvent into a nano-size is performed by a supercritical reaction.

12. The method of claim 10 , wherein the method further includes adding a filler to the nano dispersion liquid.

13. A lithium rechargeable battery comprising a positive electrode, a negative electrode, and the separator of claim 1 between the positive electrode and the negative electrode.

14. The lithium rechargeable battery of claim 13 , wherein the positive electrode includes a current collector and a positive active material and the positive active material includes nickel.

15. The lithium rechargeable battery of claim 14 , wherein in the positive active material, the nickel is included in an amount of greater than or equal to about 60 mol % based on the total amount of metal components except lithium.