Ionic liquid and power storage device including the same
An ionic liquid having high electrochemical stability and a low melting point. An ionic liquid represented by the following general formula (G0) is provided. In the general formula (G0), R 0 to R 5 are individually any of an alkyl group having 1 to 20 carbon atoms, a methoxy group, a methoxymethyl group, a methoxyethyl group, and a hydrogen atom, and A − is a univalent imide-based anion, a univalent methide-based anion, a perfluoroalkyl sulfonic acid anion, tetrafluoroborate, or hexafluorophosphate.
1. An ionic liquid represented by a general formula (G0),
wherein:
R 0 is an alkyl group having two or three carbon atoms;
R 5 is an alkyl group having one carbon atom;
one of R 1 , R 2 , and R 4 is any of an alkyl group having 1 to 20 carbon atoms, a methoxy group, a methoxymethyl group, and a methoxyethyl group;
R 3 and the others of R 1 , R 2 , and R 4 are each a hydrogen atom; and
A − is a univalent imide-based anion, a univalent methide-based anion, a perfluoroalkyl sulfonic acid anion, tetrafluoroborate, or hexafluorophosphate.
2. The ionic liquid according to claim 1 , wherein A − is any one of univalent anions selected from (C n F 2n+1 SO 2 ) 2 N − (n=0 to 4), (C m F 2m+1 SO 3 ) − (m=0 to 4), and CF 2 (CF 2 SO 2 ) 2 N − .
3. An ionic liquid represented by a general formula (G0),
wherein:
R 0 is an alkyl group having two or three carbon atoms;
R 5 is an alkyl group having one carbon atom;
two or more of R 1 to R 4 are any of an alkyl group having 1 to 20 carbon atoms, a methoxy group, a methoxymethyl group, and a methoxyethyl group;
the other of R 1 to R 4 are each a hydrogen atom; and
A − is a univalent imide-based anion, a univalent methide-based anion, a perfluoroalkyl sulfonic acid anion, tetrafluoroborate, or hexafluorophosphate.
4. The ionic liquid according to claim 1 , wherein the one of R 1 , R 2 , and R 4 is an alkyl group having 1 to 4 carbon atoms.
5. The ionic liquid according to claim 3 ,
wherein:
the ionic liquid is represented by a general formula (G2); and
R 1 and R 2 are individually any of an alkyl group having 1 to 20 carbon atoms, a methoxy group, a methoxymethyl group, and a methoxyethyl group.
6. The ionic liquid according to claim 5 , wherein R 1 and R 2 are individually an alkyl group having 1 to 4 carbon atoms.
7. The ionic liquid according to claim 1 ,
wherein:
the ionic liquid is represented by a general formula (G3); and
R 1 is any of an alkyl group having 1 to 20 carbon atoms, a methoxy group, a methoxymethyl group, and a methoxyethyl group.
8. The ionic liquid according to claim 1 ,
wherein:
the ionic liquid is represented by a general formula (G4); and
R 2 is any of an alkyl group having 1 to 20 carbon atoms, a methoxy group, a methoxymethyl group, and a methoxyethyl group.
9. The ionic liquid according to claim 1 ,
wherein:
the ionic liquid is represented by a general formula (G5); and
R 2 is any of an alkyl group having 1 to 20 carbon atoms, a methoxy group, a methoxymethyl group, and a methoxyethyl group.
10. A power storage device comprising a positive electrode, a negative electrode, a separator, and an electrolyte solution comprising an ionic liquid represented by a general formula (G0),
wherein:
R 0 is an alkyl group having two or three carbon atoms;
R 5 is an alkyl group having one carbon atom;
one of R 1 , R 2 , and R 4 is any of an alkyl group having 1 to 20 carbon atoms, a methoxy group, a methoxymethyl group, and a methoxyethyl group;
R 3 and the others of R 1 , R 2 , and R 4 are each a hydrogen atom; and
A − is a univalent imide-based anion, a univalent methide-based anion, a perfluoroalkyl sulfonic acid anion, tetrafluoroborate, or hexafluorophosphate.
11. The power storage device according to claim 10 , wherein A − is any one of univalent anions selected from (C n F 2n+1 SO 2 ) 2 N − (n=0 to 4), (C m F 2m+1 SO 3 ) − (m=0 to 4), and CF 2 (CF 2 SO 2 ) 2 N − .
12. A power storage device comprising a positive electrode, a negative electrode, a separator, and an electrolyte solution comprising an ionic liquid represented by a general formula (G0),
wherein:
R 0 is an alkyl group having two or three carbon atoms;
R 5 is an alkyl group having one carbon atom;
two or more of R 1 to R 4 are any of an alkyl group having 1 to 20 carbon atoms, a methoxy group, a methoxymethyl group, and a methoxyethyl group;
the other of R 1 to R 4 are each a hydrogen atom; and
A − is a univalent imide-based anion, a univalent methide-based anion, a perfluoroalkyl sulfonic acid anion, tetrafluoroborate, or hexafluorophosphate.
13. The power storage device according to claim 10 , wherein the one of R 1 , R 2 , and R 4 is an alkyl group having 1 to 4 carbon atoms.
14. The power storage device according to claim 12 ,
wherein:
the ionic liquid is represented by a general formula (G2); and
R 1 and R 2 are individually any of an alkyl group having 1 to 20 carbon atoms, a methoxy group, a methoxymethyl group, and a methoxyethyl group.
15. The power storage device according to claim 14 , wherein R 1 and R 2 are individually an alkyl group having 1 to 4 carbon atoms.
16. The power storage device according to claim 10 ,
wherein:
the ionic liquid is represented by a general formula (G3); and
R 1 is any of an alkyl group having 1 to 20 carbon atoms, a methoxy group, a methoxymethyl group, and a methoxyethyl group.
17. The power storage device according to claim 10 ,
wherein:
the ionic liquid is represented by a general formula (G4); and
R 2 is any of an alkyl group having 1 to 20 carbon atoms, a methoxy group, a methoxymethyl group, and a methoxyethyl group.
18. The power storage device according to claim 10 ,
wherein:
the ionic liquid is represented by a general formula (G5); and
R 2 is any of an alkyl group having 1 to 20 carbon atoms, a methoxy group, a methoxymethyl group, and a methoxyethyl group.
19. The power storage device according to claim 10 ,
wherein the electrolyte solution further comprises an electrolyte salt including a lithium ion.
20. The power storage device according to claim 10 , wherein the power storage device is a capacitor.
21. The power storage device according to claim 20 , wherein the capacitor is a lithium-ion capacitor or an electric double layer capacitor.
22. The power storage device according to claim 10 , wherein the power storage device is a lithium-ion secondary battery.
23. The ionic liquid according to claim 3 , wherein A − is any one of univalent anions selected from (C n F 2n+1 SO 2 ) 2 N − (n=0 to 4), (C m F 2m+1 SO 3 ) − (m=0 to 4), and CF 2 (CF 2 SO 2 ) 2 N − .
24. The ionic liquid according to claim 3 , wherein the two or more of R 1 to R 4 are each an alkyl group having 1 to 4 carbon atoms.
25. The power storage device according to claim 12 , wherein A − is any one of univalent anions selected from (C n F 2n+1 SO 2 ) 2 N − (n=0 to 4), (C m F 2m+1 SO 3 ) − (m=0 to 4), and CF 2 (CF 2 SO 2 ) 2 N − .
26. The power storage device according to claim 12 , wherein the two or more of R 1 to R 4 are each an alkyl group having 1 to 4 carbon atoms.
27. The power storage device according to claim 12 ,
wherein the electrolyte solution further comprises an electrolyte salt including a lithium ion.
28. The power storage device according to claim 12 , wherein the power storage device is a capacitor.
29. The power storage device according to claim 28 , wherein the capacitor is a lithium-ion capacitor or an electric double layer capacitor.
30. The power storage device according to claim 12 , wherein the power storage device is a lithium-ion secondary battery.