Composition, energy storage device, and related process
View Patent ↗A positive electrode composition is provided. The positive electrode composition includes at least one electroactive metal selected from the group consisting of titanium, vanadium, niobium, molybdenum, nickel, iron, cobalt, chromium, manganese, silver, antimony, cadmium, tin, lead, copper, zinc, and combination thereof, an alkali metal halide, and aluminum, present in an amount of at least 0.5 weight percent, based on the weight of the positive electrode composition. Optionally, an amount of sodium iodide of up to about 1.0 weight percent, based on the weight of the sodium halide in the positive electrode composition, is included. The composition may be included in a positive electrode with a molten electrolyte salt comprising the reaction product of an alkali metal halide and an aluminum halide. An energy storage device including the composition is provided, as well as a method of operating the device.
1. A positive electrode composition comprising:
at least one electroactive metal;
at least one alkali metal halide; and
aluminum present in an amount of at least about 1.0 weight percent, based on the weight of the positive electrode composition.
2. The positive electrode composition according to claim 1 , wherein the at least one electroactive metal comprises nickel.
3. The positive electrode composition according to claim 1 , wherein the alkali metal halide includes an alkali metal selected from the group of sodium, potassium, and lithium, and a halide selected from the group of chloride, bromide, and fluoride.
4. The positive electrode composition according to claim 1 , wherein the positive electrode composition further includes elemental sulfur, and/or one or more sulfides.
5. The positive electrode composition according to claim 1 , wherein the aluminum is in the form of elemental aluminum.
6. The positive electrode composition according to claim 1 , wherein the composition is included in an energy storage device.
7. The positive electrode composition according to claim 1 , wherein the composition comprises:
about 50-65 wt % of the electroactive metal, based on the weight of the positive electrode composition;
about 35-45 wt % of the alkali metal halide based on the total weight of the positive electrode composition;
at least about 1.0 wt % of the aluminum, based on the weight of the positive electrode composition; and
about 0-1 wt % sodium iodide, based on the weight of alkali metal halide in the positive electrode composition.
8. The positive electrode composition according to claim 7 , wherein:
the at least one electroactive active metal is selected from the group consisting of titanium, vanadium, niobium, molybdenum, nickel, iron, cobalt, chromium, manganese, silver, antimony, cadmium, tin, lead, copper, and zinc;
the at least one alkali metal halide is selected from the group consisting of sodium chloride, sodium iodide, sodium bromide, sodium fluoride, potassium chloride, potassium iodide, potassium bromide, potassium fluoride, lithium chloride, lithium iodide, lithium bromide, lithium fluoride, cesium chloride, and combination thereof; and
wherein the positive electrode composition further includes about 0.1-10 wt % of elemental sulfur, one or more sulfides, or a combination thereof.
9. A positive electrode composition comprising:
at least one electroactive metal;
at least one alkali metal halide other than sodium iodide;
aluminum present in an amount of at least 0.5 weight percent, based on the weight of the positive electrode composition; and
sodium iodide present in an amount up to about 1.0 weight percent of the halide content, based on the weight of alkali metal halide in the positive electrode composition.
10. The positive electrode composition according to claim 9 , wherein the at least one electroactive metal is selected from the group consisting of nickel, iron, a nickel or iron compound, and combinations thereof.
11. The positive electrode composition according to claim 9 , wherein the alkali metal halide includes an alkali metal selected from the group of sodium, potassium, and lithium, and a halide selected from the group of chloride, bromide, and fluoride.
12. The positive electrode composition according to claim 9 , wherein the positive electrode composition further includes elemental sulfur and/or one or more sulfides.
13. The positive electrode composition according to claim 9 , wherein the aluminum is in the form of elemental aluminum.
14. The positive electrode composition according to claim 9 , wherein the composition further includes one or more additives selected to provide at least one or more of the following properties: increase of ionic conductivity; increase or decrease of solubility of charged cathodic species; improve wetting of a solid electrolyte by a molten electrolyte; and preventing ripening of positive electrode micro-domains.
15. A positive electrode comprising:
a housing;
a current collector;
a positive electrode composition disposed within the housing, the composition comprising:
at least one electroactive metal;
an alkali metal halide; and
aluminum present in an amount of at least 1.0 weight percent, based on the weight of the positive electrode composition; and
a molten electrolyte salt disposed within the housing.
16. The positive electrode according to claim 15 , wherein the electroactive metal of the positive electrode composition includes nickel and the molten electrolyte salt is sodium tetrachloroaluminate.
17. The positive electrode according to claim 15 , wherein the positive electrode is part of an energy storage device that is rechargeable over a plurality of cycles.