High amperage batteries with displacement salt electrodes
An electrochemical cell includes a negative electrode comprising a first active metal, a positive electrode comprising a second active metal, and an electrolyte comprising salts of the two active metals, a salt of the cathodic metal and a salt of the anodic metal. In operation, the electrolyte composition varies such that in a charging mode the salt of the anodic salt decreases, while the salt of the cathodic salt increases, and in a discharging mode the salt of the anodic salt increases, while the salt of the cathodic salt decreases. The cell is operational for both storing electrical energy and as a source of electrical energy as part of an uninterruptible power system. The cell is particularly suited to store electrical energy produced by an intermittent renewable energy source.
1. An electrochemical cell comprising:
a negative electrode comprising lithium as a first active metal;
a positive electrode, separated from the negative electrode, comprising lead as a second active metal; and
an electrolyte, between the negative electrode and the positive electrode, comprising a salt of the first active metal and a salt of the second active metal, the electrolyte defining first and second interfaces, the negative electrode being in contact with the electrolyte at the first interface and the positive electrode being in contact with the electrolyte at the second interface, wherein the salts of the first and second active metals are selected from the group consisting of a halide, a sulfate, a carbonate, a nitrate, and combinations thereof,
wherein
at least two of the group consisting of the negative electrode, the positive electrode, and the electrolyte are in the molten state at an operating temperature of the cell,
the electrolyte composition varies such that in a charging mode, the salt of the first active metal decreases while the salt of the second active metal increases, and in a discharging mode, the salt of the first active metal increases while the salt of the second active metal decreases, and
in a charging mode the first active metal is reduced and the second active metal is oxidized, and in a discharging mode the first active metal is oxidized and the second active metal is reduced.
2. The electrochemical cell according to claim 1 , wherein the positive electrode further comprises an element selected from the group consisting of nickel, iron, copper, zinc, bismuth, tin, aluminum, cadmium, mercury, antimony, and combinations thereof.
3. The electrochemical cell according to claim 1 , wherein the positive electrode comprises an alloy having 20 mole % lead in bismuth.
4. The electrochemical cell according to claim 1 , wherein the salt of the first active metal is LiCl and wherein the salt of the second active metal is PbCl 2 .
5. The electrochemical cell according to claim 1 , wherein the salt of the first active metal is LiBr and wherein the salt of the second active metal is PbBr 2 .
6. The electrochemical cell according to claim 1 , wherein the halide is selected from the group consisting of chloride, bromide, iodide, and combinations thereof.
7. The electrochemical cell according to claim 1 , wherein the electrolyte further comprises a salt of a non-active metal.
8. The electrochemical cell according to claim 7 , wherein the non-active metal is potassium.
9. The electrochemical cell according to claim 1 , wherein the negative electrode, the positive electrode, and the electrolyte have a melting temperature independently selected from 700° C. or below.
10. The electrochemical cell according to claim 1 , wherein the negative electrode, the positive electrode, and the electrolyte have a melting temperature independently selected from 200° C. to 300° C.
11. The electrochemical cell according to claim 1 , wherein the negative electrode, the positive electrode, and the electrolyte are in the molten state at the operating temperature of the cell.
12. The electrochemical cell according to claim 1 , further comprising a container having inner walls coated with a polymer, wherein the negative electrode, the positive electrode, and the electrolyte are disposed within the container.
13. The electrochemical cell according to claim 12 , wherein the polymer is poly(oxyethylene) methacrylate-g-poly(dimethyl siloxane).
14. A method of exchanging electrical energy with an external circuit, the method comprising:
providing an electrochemical cell according to claim 1 ;
connecting the electrochemical cell to an external circuit; and
operating the external circuit so as to drive transfer of the first active metal between the negative electrode and the electrolyte, and to drive the transfer of the second active metal between the electrolyte and the positive electrode.
15. The method according to claim 14 , wherein the external circuit drives the first active metal from the negative electrode to the electrolyte and drives the second active metal from the electrolyte to the positive electrode thereby discharging the electrochemical cell.
16. The method according to claim 14 , wherein the external circuit comprises a load, a power transmission line, an electric power plant, or combinations thereof.
17. The method according to claim 16 , wherein the electric power plant harnesses electricity from the sun, wind, a river, a tide, heat, or combinations thereof.
18. The method according to claim 14 , wherein the negative electrode, the positive electrode, and the electrolyte have a melting temperature independently selected from 200° C. to 300° C.
19. The method according to claim 14 , wherein the electrochemical cell is operated at a temperature of 500° C. or below.
20. The method according to claim 14 , wherein the electrolyte further comprises a salt of a non-active metal.
21. The method according to claim 20 , wherein the non-active metal is potassium.
22. The electrochemical cell according to claim 1 , further comprising a selective ion conductive separator disposed between and in contact with the negative electrode and the positive electrode.
23. The electrochemical cell according to claim 1 , wherein the electrolyte comprises:
an anolyte comprising the salt of the first active metal, the negative electrode being in contact with the anolyte at the first interface;
a catholyte comprising the salt of the second active metal, the positive electrode being in contact with the catholyte at the second interface; and
a selective ion conductive separator disposed between, and in contact with, the anolyte and the catholyte, wherein the anolyte and catholyte compositions vary such that in a charging mode, the salt of the first active metal decreases while the salt of the second active metal increases, and in a discharging mode, the salt of the first active metal increases while the salt of the second active metal decreases.
24. An electrochemical cell comprising:
a negative electrode comprising lithium as a first active metal;
a positive electrode, separated from the negative electrode, comprising iron as a second active metal; and
an electrolyte, between the negative electrode and the positive electrode, comprising a salt of the first active metal and a salt of the second active metal, the electrolyte defining first and second interfaces, the negative electrode being in contact with the electrolyte at the first interface and the positive electrode being in contact with the electrolyte at the second interface, wherein the salts of the first and second active metals are selected from the group consisting of a halide, a sulfate, a carbonate, a nitrate, and combinations thereof,
wherein
at least two of the group consisting of the negative electrode, the positive electrode, and the electrolyte are in the molten state at an operating temperature of the cell,
the electrolyte composition varies such that in a charging mode, the salt of the first active metal decreases while the salt of the second active metal increases, and in a discharging mode, the salt of the first active metal increases while the salt of the second active metal decreases, and
in a charging mode the first active metal is reduced and the second active metal is oxidized, and in a discharging mode the first active metal is oxidized and the second active metal is reduced.
25. The electrochemical cell according to claim 24 , wherein the positive electrode further comprises an element selected from the group consisting of nickel, copper, lead, zinc, bismuth, tin, aluminum, cadmium, mercury, antimony, and combinations thereof.
26. The electrochemical cell according to claim 24 , wherein the salt of the first active metal is LiCl and wherein the salt of the second active metal is FeCl 2 electrolyte.
27. The electrochemical cell according to claim 24 , wherein the halide is selected from the group consisting of chloride, bromide, iodide, and combinations thereof.
28. The electrochemical cell according to claim 24 , wherein the electrolyte further comprises a salt of a non-active metal.
29. The electrochemical cell according to claim 28 , wherein the non-active metal is potassium.
30. The electrochemical cell according to claim 24 , wherein the negative electrode, the positive electrode, and the electrolyte have a melting temperature independently selected from 700° C. or below.
31. The electrochemical cell according to claim 24 , wherein the negative electrode, the positive electrode, and the electrolyte have a melting temperature independently selected from 200° C. to 500° C.
32. The electrochemical cell according to claim 24 , wherein the negative electrode, the positive electrode, and the electrolyte are in the molten state at the operating temperature of the cell.
33. The electrochemical cell according to claim 24 , further comprising a container having inner walls coated with a polymer, wherein the negative electrode, the positive electrode, and the electrolyte are disposed within the container.
34. The electrochemical cell according to claim 33 , wherein the polymer is poly(oxyethylene) methacrylate-g-poly(dimethyl siloxane).
35. The electrochemical cell according to claim 24 , further comprising a selective ion conductive separator disposed between and in contact with the negative electrode and the positive electrode.
36. The electrochemical cell according to claim 24 , wherein the electrolyte comprises:
an anolyte comprising the salt of the first active metal, the negative electrode being in contact with the anolyte at the first interface;
a catholyte comprising the salt of the second active metal, the positive electrode being in contact with the catholyte at the second interface; and
a selective ion conductive separator disposed between, and in contact with, the anolyte and the catholyte, wherein the anolyte and catholyte compositions vary such that in a charging mode, the salt of the first active metal decreases while the salt of the second active metal increases, and in a discharging mode, the salt of the first active metal increases while the salt of the second active metal decreases.
37. A method of exchanging electrical energy with an external circuit, the method comprising:
providing an electrochemical cell according to claim 24 ;
connecting the electrochemical cell to an external circuit; and
operating the external circuit so as to drive transfer of the first active metal between the negative electrode and the electrolyte, and to drive the transfer of the second active metal between the electrolyte and the positive electrode.
38. The method according to claim 37 , wherein the external circuit drives the first active metal from the negative electrode to the electrolyte and drives the second active metal from the electrolyte to the positive electrode thereby discharging the electrochemical cell.
39. The method according to claim 37 , wherein the external circuit comprises a load, a power transmission line, an electric power plant, or combinations thereof.
40. The method according to claim 39 , wherein the electric power plant harnesses electricity from the sun, wind, a river, a tide, heat, or combinations thereof.
41. The method according to claim 37 , wherein the negative electrode, the positive electrode, and the electrolyte have a melting temperature independently selected from 200° C. to 300° C.
42. The method according to claim 37 , wherein the electrochemical cell is operated at a temperature of 500° C. or below.
43. The method according to claim 37 , wherein the electrolyte further comprises a salt of a non-active metal.
44. The method according to claim 43 , wherein the non-active metal is potassium.