Electrolyte composition and aluminum battery containing the same

Abstract

This application provides an electrolyte composition comprising an aluminum salt, an ionic liquid, and an isocyanate compound. The anions in the aluminum salt are F-, Cl-, Br-, I-, BF4-, PF6-, [(CF3SO2)2N]-, CF3SO3-, NO3-, CH3CO2-, SO42-, C2O42-, or [B(C2O4)2]-. The ionic liquid has a structure of formula (I) as shown in the specification. The isocyanate compound has a structure of formula (II) or (III) as shown in the specification. In the electrolyte composition, the weight of the aluminum salt is greater than the weight of the ionic liquid, and the weight of the ionic liquid is greater than the weight of the isocyanate compound. This application also provides an aluminum battery comprising this electrolyte composition.

Claims

1. An electrolyte composition comprising: an aluminum salt, wherein the anion is F-, Cl-, Br-, I-, BF4-, PF6-, [(CF3SO2)2N]-, CF3SO3-, NO3-, CH3CO2-, SO42-, C2O42-, or [B(C2O4)2]-; an ionic liquid having the structure of formula (I): Formula (I) wherein R1 and R2 are each independently selected from C1-C5 alkyl or C2-C5 alkenyl; X- is selected from F-, Cl-, Br-, I-, BF4-, PF6-, [(CF3SO2)2N]-, CF3SO3-, NO3-, CH3CO2-, SO42-, C2O42-, or [B(C2O4)2]-; and an isocyanate compound having the structure of formula (II) or (III): Formula (II) n1 and n2 are each independently an integer from 1 to 3; n3 in formula (III) is an integer from 1 to 3; R3 is each independently selected from C1-C3 alkyl groups; n4 is 1 or 2; R4 is each independently a single bond or -CH2-; where, In the electrolyte composition, the weight of the aluminum salt is greater than the weight of the ionic liquid, and the weight of the ionic liquid is greater than the weight of the isocyanate compound.

2. The electrolyte composition as claimed in claim 1, wherein n1 and n2 of formula (II) are 1, R3 of formula (III) is methyl, n3 is 3, and n4 is 2.

3. The electrolyte composition as claimed in claim 2, wherein formula (II) is and formula (III) is.

4. The electrolyte composition as claimed in claim 1, wherein the isocyanate compound accounts for 0.05 wt% to 5.00 wt% of the total electrolyte composition.

5. The electrolyte composition as claimed in claim 1, wherein the aluminum salt is present in the electrolyte composition at a weight percentage between 50 wt% and 65 wt%, and the ionic liquid is present in the electrolyte composition at a weight percentage of more than 35 wt% but less than 50 wt%.

6. The electrolyte composition as claimed in claim 1, wherein the aluminum salt is AlF2, AlF3, AlCl2, AlCl3, AlBr2, AlBr3, AlI2 or AlI3, and the X- in formula (I) is the same as the anion in the aluminum salt.

7. The electrolyte composition as claimed in claim 6, wherein the aluminum salt is AlF3, AlCl3, AlBr3 or AlI3, and R1 and R2 in formula (I) are each independently selected from C1-C3 alkyl groups.

8. The electrolyte composition as claimed in claim 7, wherein the aluminum salt is AlCl3 and the ionic liquid is 1-ethyl-3-methylimidazolium chloride.

9. The electrolyte composition as claimed in claim 1, wherein it does not contain a lithium salt.

10. The electrolyte composition as claimed in claim 9, wherein the lithium salt is LiPF6, LiBF4, LiClO4, LiCF3SO3 or LiAsF6.

11. The electrolyte composition as claimed in claim 1, comprising the aluminum salt, the ionic liquid, and the isocyanate compound.

12. An aluminum battery comprising: a positive electrode; a separator; a negative electrode separated from the positive electrode by the separator; and an electrolyte composition as described in any one of claims 1 to 11 disposed between the positive electrode and the negative electrode, wherein the separator is immersed in the electrolyte composition.

13. The aluminum battery of claim 12, wherein the positive electrode comprises a metal substrate coated with graphite slurry or transition metal oxide.

14. The aluminum battery as claimed in claim 13, wherein the positive electrode comprises a nickel foil coated with graphite slurry.

15. The aluminum battery as claimed in claim 12, wherein the negative electrode comprises a metal or an alloy of the metal.

16. The aluminum battery as claimed in claim 15, wherein the negative electrode comprises aluminum foil, copper foil, or nickel foil.

17. The aluminum battery as claimed in claim 12, wherein the separator comprises glass fiber, polyethylene fiber, polypropylene fiber, polyether ether resin fiber, nonwoven fabric, wood fiber, ceramic fiber, or a combination thereof.

18. The aluminum battery of claim 12, wherein the aluminum salt is AlCl3, the ionic liquid is 1-ethyl-3-methylimidazolium chloride, formula (II) is, formula (III) is, and the proportion of the isocyanate compound is 0.10 wt%-1.00 wt% of the total electrolyte composition.

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