Electrolyte for rechargeable electrochemical cell
The present invention provides an aqueous electrolyte for use in rechargeable zinc-halide storage batteries that possesses improved stability and durability and improves zinc-halide battery performance. One aspect of the present invention provides an electrolyte for use in a secondary zinc bromine electrochemical cell comprising from about 30 wt % to about 40 wt % of ZnBr 2 by weight of the electrolyte; from about 5 wt % to about 15 wt % of KBr; from about 5 wt % to about 15 wt % of KCl; and one or more quaternary ammonium agents, wherein the electrolyte comprises from about 0.5 wt % to about 10 wt % of the one or more quaternary ammonium agents.
1. An electrolyte for use in a secondary static zinc halide electrochemical cell comprising:
an aggregate concentration of from about 2.0 wt % to about 15.0 wt % of one or more quaternary ammonium agents,
wherein the one or more quaternary ammonium agents comprises:
at least one of cetyltrimethylammonium chloride or cetyltrimethylammonium bromide, and
at least one of an alkyl substituted pyridinium chloride or an alkyl substituted pyridinium bromide.
2. The electrolyte of claim 1 , further comprising from about 0.2 wt % to about 1.2 wt % of the cetyltrimethylammonium chloride or cetyltrimethylammonium bromide.
3. The electrolyte of claim 2 , further comprising from about 1.8 wt % to about 7.5 wt % of the alkyl substituted pyridinium chloride or the alkyl substituted pyridinium bromide.
4. The electrolyte of claim 3 , further comprising from about 2.0 wt % to about 6.0 wt % of the alkyl substituted pyridinium chloride or the alkyl substituted pyridinium bromide.
5. The electrolyte of claim 4 , further comprising from about 2.0 wt % to about 6.0 wt % of alkyl substituted pyridinium bromide, wherein the alkyl substituted pyridinium bromide is selected from the group consisting of 1-ethyl-2-methylpyridinium bromide, 1-ethyl-3-methylpyridinium bromide, and 1-ethyl-4-methylpyridinium bromide.
6. The electrolyte of claim 5 , further comprising from about 0.05 wt % to about 0.2 wt % of 1,1-dioctadecyl-4-4′bypyridinium chloride or from about 0.05 wt % to about 0.2 wt % of 1,1-dioctadecyl-4-4′bypyridinium bromide.
7. The electrolyte of claim 1 , further comprising from about 25 wt % to about 40 wt % of ZnBr 2 .
8. The electrolyte of claim 1 , further comprising from about 25 wt % to about 45 wt % of water.
9. The electrolyte of claim 1 , further comprising from about 1 wt % to about 5 wt % of KBr.
10. The electrolyte of claim 9 , further comprising from about 5 wt % to about 15 wt % of KCI.
11. The electrolyte of claim 1 , further comprising from about 0.5 wt % to about 2.5 wt % of an ether, wherein the ether is at least one of DME-PEG or dimethyl ether.
12. The electrolyte according to claim 11 , wherein the ether is DME-PEG, and the DME-PEG has an average molecular weight of from about 350 amu to about 3000 amu.
13. The electrolyte according to claim 12 , wherein the DME-PEG has an average molecular weight of from about 750 amu to about 2500 amu.
14. The electrolyte according to claim 13 , wherein the ether is DME-PEG, and the electrolyte comprises from about 0.1 wt % to about 0.5 wt % of DME-PEG having an average molecular weight of from about 750 amu to about 1250 amu.
15. The electrolyte according to claim 13 , wherein the ether is DME-PEG, and the electrolyte comprises from about 1.0 wt % to about 2.0 wt % of DME-PEG having an average molecular weight of from about 1750 amu to about 2250 amu.
16. The electrolyte of claim 1 , further comprising from about 2 wt % to about 6 wt % of tetraethylammonium chloride or tetraethylammonium bromide.
17. The electrolyte of claim 16 , further comprising from about 2 wt % to about 6 wt % of the tetraethylammonium bromide.
18. The electrolyte of claim 17 , further comprising N-ethyl-N-methylmorpholinium chloride or N-ethyl-N-methylmorpholinium bromide.
19. The electrolyte of claim 18 , further comprising from about 0.5 wt % to about 2.0 wt % of the N-ethyl-N-methylmorpholinium chloride or N-ethyl-N-methylmorpholinium bromide.
20. The electrolyte of claim 19 , further comprising from about 25 wt % to about 40 wt % of ZnBr 2 .
21. The electrolyte of claim 20 , further comprising from about 25 wt % to about 45 wt % of water.
22. The electrolyte of claim 21 , further comprising from about 2 wt % to about 10 wt % of KBr.
23. The electrolyte of claim 22 , further comprising from about 5 wt % to about 15 wt % of KCI.
24. The electrolyte of claim 23 , further comprising from about 0.5 wt % to about 2.5 wt % of an ether, wherein the ether is at least one of DME-PEG or dimethyl ether.
25. The electrolyte according to claim 24 , wherein the ether is DME-PEG, and the DME-PEG has an average molecular weight of from about 350 amu to about 3000 amu.
26. The electrolyte according to claim 24 , wherein the DME-PEG has an average molecular weight of from about 750 amu to about 2500 amu.
27. The electrolyte according to claim 26 , wherein the ether is DME-PEG, and the electrolyte comprises from about 0.1 wt % to about 0.5 wt % of DME-PEG having an average molecular weight of from about 750 amu to about 1250 amu.
28. The electrolyte according to claim 26 , wherein the ether is DME-PEG, and the electrolyte comprises from about 1.0 wt % to about 2.0 wt % of DME-PEG having an average molecular weight of from about 1750 amu to about 2250 amu.
29. An electrolyte for use in a secondary zinc bromine electrochemical cell comprising:
from about 25 wt % to about 40 wt % of ZnBr 2 ;
from about 25 wt % to about 45 wt % of water; and
one or more quaternary ammonium agents,
wherein the electrolyte has an aggregate concentration of from about 2.0 wt % to about 15.0 wt % of the one or more quaternary ammonium agents, and wherein the one or more quaternary ammonium agents comprises at least
cetyltrimethylammonium bromide, and
an alkyl substituted pyridinium bromide.
30. The electrolyte of claim 29 , further comprising from about 0.2 wt % to about 1.2 wt % of cetyltrimethylammonium bromide and from about 1.8 wt % to about 7.5 wt % of the alkyl substituted pyridinium bromide.
31. The electrolyte of claim 30 , further comprising from about 0.05 wt % to about 0.2 wt % of 1,1-dioctadecyl-4-4′bypyridinium chloride or from about 0.05 wt % to about 0.2 wt % of 1,1-dioctadecyl-4-4′bypyridinium bromide.
32. The electrolyte of claim 31 , further comprising from about 1 wt % to about 5 wt % of KBr.
33. The electrolyte of claim 32 , further comprising from about 5 wt % to about 15 wt % of KCI.
34. The electrolyte of claim 33 , further comprising from about 0.1 wt % to about 0.5 wt % of DME-PEG having an average molecular weight of from about 750 amu to about 1250 amu.
35. The electrolyte of claim 34 , further comprising from about 1.0 wt % to about 2.0 wt % of DME-PEG having an average molecular weight of from about 1750 amu to about 2250 amu.
36. The electrolyte of claim 35 , further comprising an acid, or the conjugate base of an acid, selected from the group consisting of acetic acid, nitric acid, and citric acid.
37. The electrolyte of claim 36 , further comprising from about 0.1 wt % to about 1.0 wt % of glacial acetic acid or from about 0.1 wt % to about 1.0 wt % of HBr.
38. The electrolyte of claim 1 , further comprising from about 1.0 wt % to about 5 wt % of a glyme, wherein the glyme is at least one of diglyme, triglyme, or tetraglyme.
39. The electrolyte of claim 29 , wherein the alkyl substituted pyridinium bromide is at least one of 1-ethyl-2-methylpyridinium bromide, 1-ethyl-3-methylpyridinium bromide, or 1-ethyl-4-methylpyridinium bromide.