Cosolvent electrolytes for electrochemical devices
View Patent ↗A system and method for stabilizing electrodes against dissolution and/or hydrolysis including use of cosolvents in liquid electrolyte batteries for three purposes: the extension of the calendar and cycle life time of electrodes that are partially soluble in liquid electrolytes, the purpose of limiting the rate of electrolysis of water into hydrogen and oxygen as a side reaction during battery operation, and for the purpose of cost reduction.
1. An electrolyte solution for an electrochemical system, comprising:
a cosolvent liquid including a first liquid solvent combined with a second liquid solvent and a salt;
wherein said cosolvent liquid includes a total liquid volume V;
wherein said total liquid volume V includes a first liquid volume fraction V1 of said first liquid solvent;
wherein said total liquid volume V includes a second liquid volume fraction V2 of said second liquid solvent;
wherein V=V1+V2;
wherein said first volume fraction V1 consists essentially of H 2 O;
wherein said second volume fraction V2 includes one or more organic solvents;
wherein V1/V>0.02;
wherein V2>V1; and
wherein said cosolvent liquid consists essentially of a single phase.
2. The electrolyte solution of claim 1 wherein said total liquid volume V includes one or more cations selected from the group consisting of an alkali cation, an alkali earth cation, an ammonium cation, and combinations thereof.
3. The electrolyte solution of claim 2 wherein said electrolyte produces a total concentration of said plurality of cations in said total liquid volume V greater than 0.1 M.
4. The electrolyte solution of claim 3 wherein said total concentration is greater than 1.4 M.
5. The electrolyte solution of claim 1 wherein said total liquid volume V includes an additive; wherein an electrode disposed within said total liquid volume V includes a first lifetime when disposed in said total liquid volume V, wherein said electrode includes a second lifetime when disposed in said total liquid volume without said additive, and wherein said lifetime is greater than said second lifetime.
6. The electrolyte solution of claim 1 wherein said total liquid volume V includes one or more polar aprotic solvents.
7. The electrolyte solution of claim 6 wherein said one or more polar aprotic solvents include one or more organic polar aprotic cosolvents.
8. The electrolyte solution of claim 7 wherein said one or more organic polar aprotic cosolvents include a particular cosolvent having one or more cyanide groups.
9. The electrolyte solution of claim 8 wherein said particular cosolvent includes acetonitrile.
10. The electrolyte solution of claim 7 wherein said one or more organic polar aprotic cosolvents include a particular cosolvent having one or more carbonate groups.
11. The electrolyte solution of claim 10 wherein said particular cosolvent is selected from the group consisting of ethylene carbonate, propylene carbonate, dimethyl carbonate, and combinations thereof.
12. The electrolyte solution of claim 1 wherein said total liquid volume V includes one or more organic polar protic solvents.
13. The electrolyte solution of claim 12 wherein said one or more organic polar protic solvents include a particular solvent having one or more alcohol groups.
14. The electrolyte solution of claim 13 wherein said particular solvent is selected from the group consisting of methanol, ethylene glycol, glycerol, hydroxypropionitrile, and combinations thereof.
15. The electrolyte solution of claim 10 wherein said total liquid volume V includes one or more organic polar protic solvents.
16. The electrolyte solution of claim 1 wherein V1/V≤30% and V2/V≥70%.
17. The electrolyte solution of claim 16 wherein V1/V≤10% and V2/V≥90%.
18. The electrolyte solution of claim 7 wherein said total liquid volume V includes both a cyanide-containing cosolvent and a carbonate-containing cosolvent.
19. The electrolyte solution of claim 7 wherein said one of more organic polar aprotic cosolvents include a particular cosolvent having one or more sulfone groups.
20. The electrolyte solution of claim 19 wherein said particular cosolvent includes sulfolane.
21. The electrolyte solution of claim 7 wherein said total liquid volume V includes both a cyanide-containing cosolvent and a sulfone-containing cosolvent.
22. The electrolyte solution of claim 7 wherein said one or more organic polar aprotic cosolvents include a particular cosolvent having one or more ketone groups.
23. The electrolyte solution of claim 22 wherein said particular cosolvent includes acetone.
24. An electrolyte solution for an electrochemical system, comprising:
a cosolvent liquid including a first liquid solvent combined with a second liquid solvent and a salt;
wherein said cosolvent liquid includes a total liquid metric X;
wherein said total liquid metric X includes a first liquid metric fraction X1 of said first liquid solvent;
wherein said total liquid metric X includes a second liquid metric fraction X2 of said second liquid solvent;
wherein X=X1+X2;
wherein said first liquid metric fraction X1 consists essentially of H 2 O;
wherein said second liquid metric fraction X2 includes one or more organic solvents;
wherein X1/X>0.02;
wherein X2>X1; and
wherein said cosolvent liquid consists essentially of a single phase.
25. The electrolyte solution of claim 24 wherein said total liquid metric X includes a total liquid volume, wherein said first liquid metric fraction X1 includes a first liquid volume fraction, and wherein said second liquid metric fraction X2 includes a second liquid volume fraction.
26. The electrolyte solution of claim 24 wherein said total liquid metric X includes a total liquid quantity, wherein said first liquid metric fraction X1 includes a first liquid quantity fraction, and wherein said second liquid metric fraction X2 includes a second liquid quantity fraction.
27. The electrolyte solution of claim 24 wherein said total liquid metric X includes a total liquid weight, wherein said first liquid metric fraction X1 includes a first liquid weight fraction, and wherein said second liquid metric fraction X2 includes a second liquid weight fraction.
28. The electrolyte solution of claim 24 wherein second liquid metric fraction X2 includes a first liquid metric subfraction X3 and a second liquid metric subfraction X4 wherein X3+X4=X2, wherein said first liquid metric subfraction X3 includes a first organic cosolvent, and wherein said second liquid metric subfraction X4 includes a second organic cosolvent different from said first organic cosolvent.
29. The electrolyte solution of claim 28 wherein said first organic cosolvent includes MeCN, and wherein said second organic cosolvent includes a solvent selected from the group consisting essentially of sulfolane, propylene glycol monoethyl ether, hydroxypropionitrile, gamma-valerolactone, ethylene carbonate, dimethyl carbonate, propylene carbonate, and 1,3-dioxolan.
30. The electrolyte solution of claim 29 wherein X1/X=0.05, wherein X3/ X≥0.10, and wherein X4/X≥0.85.