Solid electrolyte and method for manufacturing same
The present invention relates to a polymer electrolyte and a method for manufacturing same. More specifically, a polymer electrolyte with improved ion conductivity can be produced by adding boron nitride to a solid electrolyte comprising polysiloxane.
1. A solid electrolyte comprising:
a polysiloxane; and
boron nitride (BN),
wherein the boron nitride is a boron nitride surface-modified with polycyclic aromatic hydrocarbon.
2. The solid electrolyte according to claim 1 , wherein the solid electrolyte further comprises a lithium salt; and an organic solvent; wherein the polysiloxane is a polymer matrix and the boron nitride (BN) is a filler.
3. The solid electrolyte according to claim 1 , wherein the boron nitride is contained in an amount of 0.1 to 5% by weight based on the weight of the polysiloxane.
4. The solid electrolyte according claim 1 , wherein the polycyclic aromatic hydrocarbon is at least one selected from the group consisting of pyrene, perylene and benzoperylene.
5. The solid electrolyte according claim 1 , wherein the polycyclic aromatic hydrocarbon is one whose end is modified by a combination of polyethylene glycol (PEG).
6. The solid electrolyte according claim 1 , wherein the polycyclic aromatic hydrocarbon is contained in an amount of 4 to 10% by weight based on the total weight of the surface-modified boron nitride.
7. The solid electrolyte according to claim 1 , wherein the molecular weight of the polysiloxane is 800 to 1200 g/mol.
8. The solid electrolyte according to claim 2 , wherein the lithium salt is at least one selected from the group consisting of LiN(SO 2 CF 3 ) 2 (LiTFSI), LiSCN, LiN(CN) 2 , LiClO 4 , LiBF 4 , LiAsF 6 , LiPF 6 , LiCF 3 SO 3 , Li(CF 3 SO 2 ) 3 C, LiN(SO 2 CF 3 ) 2 , LiN(SO 2 CF 2 CF 3 ) 2 , LiSbF 6 , LiPF 3 (CF 2 CF 3 ) 3 , LiPF 3 (C 2 F 5 ) 3 , LiPF 3 (CF 3 ) 3 , and LiB(C 2 O 4 ) 2 .
9. The solid electrolyte according to claim 2 , wherein the organic solvent is at least one selected from the group consisting of methanol, acetone, 4-acetylmorpholine, 2-methylpyridine-1-oxide, 2-pyrrolidon, 1-(2-hydroxyethyl)-2-pyrrolidinone, propylene carbonate (PC), ethylene carbonate (EC), 2-oxepanone, butanone, 2-pentanone, methyl ethyl ketone (MEK) and methoxynonafluorobutane.
10. The solid electrolyte according to claim 2 , wherein the solid electrolyte further comprises a crosslinking agent comprising tetraallyl oxy ethane (TAOE).
11. A method for preparing a solid electrolyte comprising the steps of:
(S1) reacting a boron nitride with a polycyclic aromatic hydrocarbon to form a surface-modified boron nitride;
(S2) dissolving a polysiloxane, a crosslinking agent and a photo-initiator in an organic solvent to form a mixed solution;
(S3) adding the surface-modified boron nitride and a lithium salt to the mixed solution to form a slurry; and
(S4) casting the slurry onto a substrate and then curing the slurry.
12. The method for preparing the solid electrolyte according to claim 11 , wherein the initiator is at least one photo-initiator selected from the group consisting of 2,2-dimethoxy-2-phenylacetophenone, 1-hydroxy-cyclohexyl phenyl ketone and 2,4,6-trimethylbenzoyldiphenyl-phosphineoxide.
13. A lithium secondary battery comprising the solid electrolyte of claim 1 .
14. The solid electrolyte according to claim 1 , wherein the polysiloxane is contained in an amount of 15 to 20% by weight based on the weight of the solid electrolyte.
15. The solid electrolyte according to claim 1 , wherein the solid electrolyte further comprises at least a polymer selected from the group consisting of allyl polyethylene glycol (APEG), polyethylene glycol (PEG), ethylene glycol (EG) and polyethylene glycol diacrylate (PEGDA).
16. The solid electrolyte according to claim 1 , wherein the boron nitride is contained in an amount of 0.1 to 3% by weight based on the weight of the polysiloxane.
17. The solid electrolyte according to claim 1 , wherein the boron nitride is contained in an amount of 0.1 to 1% by weight based on the weight of the polysiloxane.
18. The solid electrolyte according to claim 10 , wherein the crosslinking agent is contained in an amount of 5 to 10% by weight based on the weight of the solid electrolyte.