Power storage device, lithium-ion secondary battery, electric double layer capacitor and lithium-ion capacitor
One object is to provide a power storage device including an electrolyte using a room-temperature ionic liquid which includes a univalent anion and a cyclic quaternary ammonium cation having excellent reduction resistance. Another object is to provide a high-performance power storage device. A room-temperature ionic liquid which includes a cyclic quaternary ammonium cation represented by a general formula (G1) below is used for an electrolyte of a power storage device. In the general formula (G1), one or two of R 1 to R 5 are any of an alkyl group having 1 to 20 carbon atoms, a methoxy group, a methoxymethyl group, and a methoxyethyl group. The other three or four of R 1 to R 5 are hydrogen atoms. A − is a univalent imide anion, a univalent methide anion, a perfluoroalkyl sulfonic acid anion, tetrafluoroborate (BF 4 − ), or hexafluorophosphate (PF 6 − ).
1. A power storage device comprising:
a positive electrode;
a negative electrode;
a separator;
an electrolyte salt; and
an ionic liquid represented by a general formula (G2)
wherein R 2 represents an alkyl group having 1 to 4 carbon atoms,
wherein R 1 represents a hydrogen atom,
wherein A − represents a univalent imide anion 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 − , and
wherein the electrolyte salt includes a lithium ion.
2. The power storage device according to claim 1 , wherein the power storage device is a lithium-ion secondary battery.
3. The power storage device according to claim 1 , wherein the power storage device is a lithium-ion capacitor.
4. The power storage device according to claim 1 , wherein the A − is (FSO 2 ) 2 N − or (CF 3 SO 2 ) 2 N − .
5. The power storage device according to claim 1 , the power storage device further comprising:
a first solvent,
wherein the first solvent is a room-temperature ionic liquid other than the ionic liquid represented by the general formula (G2).
6. An electronic appliance comprising the power storage device according to claim 1 .
7. An electric propulsion vehicle comprising the power storage device according to claim 1 .
8. A power storage device comprising:
a positive electrode;
a negative electrode;
a separator;
an electrolyte salt; and
an ionic liquid represented by a general formula (G4)
wherein A − represents a univalent imide anion 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 − , and
wherein the electrolyte salt includes a lithium ion.
9. The power storage device according to claim 8 , wherein the power storage device is a lithium-ion secondary battery.
10. The power storage device according to claim 8 , wherein the power storage device is a lithium-ion capacitor.
11. The power storage device according to claim 8 , wherein the A − is (FSO 2 ) 2 N − or (CF 3 SO 2 ) 2 N − .
12. The power storage device according to claim 8 , the power storage device further comprising:
a first solvent,
wherein the first solvent is a room-temperature ionic liquid other than the ionic liquid represented by the general formula (G4).
13. An electronic appliance comprising the power storage device according to claim 8 .
14. An electric propulsion vehicle comprising the power storage device according to claim 8 .