Electrode compositions, energy storage devices and related methods

1. A positive electrode composition, comprising:

at least one electroactive metal;

at least one sodium halide; and

at least one additive comprising a plurality of nanoparticles, wherein the plurality of nanoparticles comprises tungsten carbide.

2. The positive electrode composition of claim 1 , wherein the at least one additive is present in an amount in a range from about 0.1 weight percent to about 5 weight percent of the positive electrode composition.

3. The positive electrode composition of claim 1 , wherein the at least one additive is present in an amount in a range from about 0.25 weight percent to about 2.5 weight percent of the positive electrode composition.

4. The positive electrode composition of claim 1 , wherein the plurality of nanoparticles have an average particle size in a range from about 10 nanometers to about 1000 nanometers.

5. The positive electrode composition of claim 1 , wherein the at least one electroactive metal is selected from the group consisting of titanium, vanadium, niobium, molybdenum, nickel, cobalt, chromium, copper, manganese, silver, antimony, cadmium, tin, lead, iron, zinc, and combinations thereof.

6. The positive electrode composition of claim 1 , wherein the at least one electroactive metal comprises nickel.

7. The positive electrode composition of claim 1 , wherein the positive electrode composition comprises at least two electroactive metals.

8. The positive electrode composition of claim 7 , wherein the at least two electroactive metals comprise nickel and iron.

9. The positive electrode composition of claim 1 , wherein the at least one sodium halide comprises a chloride, bromide, or fluoride.

10. The positive electrode composition of claim 1 , wherein the positive electrode composition comprises the at least one sodium halide and at least one additional alkali metal halide.

11. The positive electrode composition of claim 10 , comprising sodium chloride and sodium iodide.

12. The positive electrode composition of claim 1 further comprising a metal sulfide.

13. The positive electrode composition of claim 1 , further comprising an electrolyte.

14. An article, comprising:

a positive electrode; which itself comprises:

at least one electroactive metal;

at least one sodium halide;

at least one additive comprising a plurality of nanoparticles, wherein the plurality of nanoparticles comprises tungsten carbide.

15. The article of claim 14 , in the form of an energy storage device or an uninterruptable power supply (UPS) device.

16. An energy storage device, comprising:

(a) a first compartment comprising an alkali metal;

(b) a negative electrode current collector;

(c) a second compartment comprising a positive electrode composition, the positive cathode composition comprising:

at least one electroactive metal;

at least one sodium halide;

at least one additive comprising a plurality of nanoparticles, wherein the plurality of nanoparticles comprises tungsten carbide; and

at least one electrolyte;

(d) a positive electrode current collector; and

(e) a solid separator capable of transporting alkali metal ions between the first and the second compartments.

17. The energy storage device of claim 16 , wherein the additive is present in an amount in a range from about 0.1 weight percent to about 5 weight percent of the positive electrode composition.

18. The energy storage device of claim 16 , wherein the electroactive metal is selected from the group consisting of titanium, vanadium, niobium, molybdenum, nickel, cobalt, chromium, copper, manganese, silver, antimony, cadmium, tin, lead, iron, zinc, and combinations thereof.

19. The energy storage device of claim 16 , wherein the second compartment is disposed within the first compartment.

20. The energy storage device of claim 16 , wherein the first compartment is disposed within the second compartment.

21. The energy storage device of claim 16 , characterized as being rechargeable over a plurality of cycles.

22. An energy storage battery comprising a plurality of rechargeable energy storage devices in accordance with claim 16 .

23. A method for the preparation of an energy storage device, comprising:

(i) providing a housing having an interior surface defining a volume;

(ii) disposing a separator inside the housing, wherein the separator has a first surface that defines at least a portion of a first compartment, and a second surface that defines a second compartment, wherein the first compartment is in ionic communication with the second compartment through the separator;

(iii) disposing a positive electrode composition in the second compartment, wherein the positive electrode composition comprises:

at least one electroactive metal;

at least one sodium halide; and

at least one additive comprising a plurality of nanoparticles, wherein the plurality of nanoparticles comprises tungsten carbide.