Electrolyte additive and non-aqueous electrolyte solution for lithium secondary battery comprising the same
View Patent ↗The present invention relates to a non-aqueous electrolyte solution additive, and a non-aqueous electrolyte solution for a lithium secondary battery and a lithium secondary battery which comprise the same, wherein, specifically, since the non-aqueous electrolyte solution, which comprises a compound capable of maintaining a passive effect by increasing an effect of forming a solid electrolyte interface (SEI) on surfaces of a positive electrode and a negative electrode, is provided, high-temperature storage characteristics and life characteristics of the lithium secondary battery may be improved.
1. An electrolyte additive comprising a compound represented by Formula 1:
wherein, in Formula 1,
X 1 and X 2 are phosphorus (P),
Y 1 to Y 4 are each independently oxygen (O) or sulfur (S),
L is a direct bond or a divalent hydrocarbon group having 1 to 10 carbon atoms, and
R 1 to R 4 are each independently hydrogen, a halogen atom, a nitrile group, or a monovalent hydrocarbon group having 1 to 20 carbon atoms, and at least one of R 1 to R 4 is a halogen atom,
wherein the divalent hydrocarbon group having 1 to 10 carbon atoms and the monovalent hydrocarbon group having 1 to 20 carbon atoms are substituted or unsubstituted, and the substitution is performed with at least one substituent selected from the group consisting of an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, an alkynyl group having 2 to 20 carbon atoms, and an aryl group having 6 to 20 carbon atoms.
2. The electrolyte additive of claim 1 , wherein, in the compound represented by Formula 1,
L is a substituted or unsubstituted alkylene group having 1 to 10 carbon atoms, and
R 1 to R 4 are each independently a halogen atom or a substituted or unsubstituted monovalent hydrocarbon group having 1 to 20 carbon atoms.
3. The electrolyte additive of claim 1 , wherein the compound represented by Formula 1 is selected from compounds represented by Formula 1a or Formula 1b:
4. A non-aqueous electrolyte solution for a lithium secondary battery, the non-aqueous electrolyte solution comprising:
a lithium salt, an organic solvent, and a first additive,
wherein the first additive is the electrolyte additive of claim 1 .
5. The non-aqueous electrolyte solution for a lithium secondary battery of claim 4 , wherein the first additive is comprised in an amount of 0.1 wt % to 6 wt % based on a total weight of the non-aqueous electrolyte solution.
6. The non-aqueous electrolyte solution for a lithium secondary battery of claim 5 , wherein the first additive is comprised in an amount of 0.5 wt % to 5 wt % based on the total weight of the non-aqueous electrolyte solution.
7. The non-aqueous electrolyte solution for a lithium secondary battery of claim 4 , further comprising a second additive selected from the group consisting of a non-lithiated additive, a lithiated additive, and a mixture thereof.
8. The non-aqueous electrolyte solution for a lithium secondary battery of claim 7 , wherein the non-lithiated additive comprises at least one selected from the group consisting of a carbonate-based compound, a phosphate-based compound, a borate-based compound, a silane-based compound, a sulfur-containing compound, a nitrile-based compound, and a fluorobenzene-based compound.
9. The non-aqueous electrolyte solution for a lithium secondary battery of claim 7 , wherein the non-lithiated additive is comprised in an amount of 0.01 wt % to 10 wt % based on a total weight of the non-aqueous electrolyte solution.
10. The non-aqueous electrolyte solution for a lithium secondary battery of claim 7 , wherein the lithiated additive comprises at least one selected from the group consisting of boron halide-based lithium, boron oxalate-based lithium, imidazole-based lithium, phosphate-based lithium, and sulfate-based lithium.
11. The non-aqueous electrolyte solution for a lithium secondary battery of claim 7 , wherein the lithiated additive is comprised in an amount of 0.01 wt % to 10 wt % based on a total weight of the non-aqueous electrolyte solution.
12. A lithium secondary battery comprising the non-aqueous electrolyte solution for a lithium secondary battery of claim 4 .
13. The electrolyte additive of claim 1 , wherein, in the compound represented by Formula 1,
Y 1 to Y 4 are each independently oxygen (O),
L is a substituted or unsubstituted alkylene group having 1 to 10 carbon atoms, and
R 1 to R 4 are each independently a halogen atom.
14. The non-aqueous electrolyte solution for a lithium secondary battery of claim 7 , wherein the non-lithiated additive comprises at least one carbonate-based compound selected from the group consisting of vinylene carbonate, fluoroethylene carbonate, difluoroethylene carbonate, and vinyl ethylene carbonate, which are unsubstituted or substituted with an alkyl group having 1 to 3 carbon atoms.
15. The non-aqueous electrolyte solution for a lithium secondary battery of claim 7 , wherein the non-lithiated additive comprises at least one borate-based compound represented by Formula 3:
wherein, in Formula 3,
A 4 to A 6 are each independently —Si(R c ) m (R d ) 3-m , or a propynyl group (—C≡C), wherein R c and R d are each independently an alkyl group having 1 to 4 carbon atoms, and m is an integer of 0 to 3.
16. The non-aqueous electrolyte solution for a lithium secondary battery of claim 7 , wherein the lithiated additive comprises at least one boron halide-based lithium selected from the group consisting of lithium tetrafluoro borate, lithium tetrachloro borate, lithium chlorotrifluoro borate, lithium trichlorofluoro borate, and lithium dichlorodifluoro borate.
17. The non-aqueous electrolyte solution for a lithium secondary battery of claim 7 , wherein the lithiated additive comprises at least one boron oxalate-based lithium selected from the group consisting of lithium bis(oxalato)borate, lithium difluoro(oxalato)borate, and lithium dichloro(oxalato)borate.
18. The non-aqueous electrolyte solution for a lithium secondary battery of claim 7 , wherein the lithiated additive comprises at least one phosphate-based lithium selected from the group consisting of lithium dihalo phosphate, lithium dialkyl phosphate, lithium dihalo(bisoxalato) phosphate, and lithium dialkyl(bisoxalato) phosphate, wherein the dihalo refers to two halogen substituents, which are each independently F or Cl, and the dialkyl refers to two alkyl substituents, which are each independently an alkyl group having 1 to 3 carbon atoms.
19. The non-aqueous electrolyte solution for a lithium secondary battery of claim 4 , wherein the lithium salt comprises Li + as a cation, and at least one selected from the group consisting of F − , Cl − , Br − , I − , NO 3 − , N(CN) 2 − , BF 4 − , ClO 4 − , AlO 4 − , AlCl 4 − , PF 6 − , SbF 6 − , AsF 6 − , B 10 Cl 10 —, BF 2 C 2 O 4 − , BC 4 O 8 − , PF 4 C 2 O 4 − , PF 2 C 4 O 8 − , (CF 3 ) 2 PF 4 − , (CF 3 ) 3 PF 3 − , (CF 3 ) 4 PF 2 − , (CF 3 ) 5 PF − , (CF 3 ) 6 P − , CF 3 SO 3 − , C 4 F 9 SO 3 − , CF 3 CF 2 SO 3 − , (CF 3 SO 2 ) 2 N − , (FSO 2 ) 2 N − , CF 3 CF 2 (CF 3 ) 2 CO − , (CF 3 SO 2 ) 2 CH − , CH 3 SO 3 − , CF 3 (CF 2 ) 7 SO 3 − , CF 3 CO 2 − , CH 3 CO 2 − , SCN − , and (CF 3 CF 2 SO 2 ) 2 N − as an anion.
20. The non-aqueous electrolyte solution for a lithium secondary battery of claim 4 , wherein the organic solvent comprises at least one selected from the group consisting of an ether-based solvent, an ester-based organic solvent, and an amide-based organic solvent.