Rechargeable metal halide battery

1. A battery, comprising:

an anode;

an electrolyte comprising,

an oxidizing gas,

a metal halide as an active cathode material, and

a solvent comprising a nitrile compound, wherein the oxidizing gas and the metal halide are dissolved in the solvent and the electrolyte is in contact with the anode; and

a current collector in contact with the active cathode material.

2. The battery of claim 1 , wherein the current collector comprises a porous material that is electrically conductive.

3. The battery of claim 1 , comprising a separator between the anode and the current collector.

4. The battery of claim 1 , wherein the battery completes at least 100 cycles of charging and discharging at a current density of greater than or equal to 1 mA/cm 2 .

5. The battery of claim 1 , wherein the battery completes at least 1000 cycles of charging and discharging at a current density of greater than or equal to 1 mA/cm 2 .

6. The battery of claim 1 , wherein the battery completes at least 100 cycles of charging and discharging at a current density of greater than or equal to 20 mA/cm 2 .

7. The battery of claim 1 , wherein the battery completes at least 1000 cycles of charging and discharging at a current density of greater than or equal to 20 mA/cm 2 .

8. The battery of claim 1 , wherein the battery has an energy efficiency of greater than or equal to 90% at a current density of greater than or equal to 1 mA/cm 2 .

9. The battery of claim 1 , wherein the battery has an energy efficiency of greater than or equal to 99% at a current density of greater than or equal to 1 mA/cm 2 .

10. The battery of claim 1 , wherein the battery has an energy efficiency of greater than or equal to 90% at a current density of greater than or equal to 20 mA/cm 2 .

11. The battery of claim 1 , wherein the battery has an energy efficiency of greater than or equal to 99% at a current density of greater than or equal to 20 mA/cm 2 .

12. The battery of claim 1 , wherein the anode comprises at least one of Li, Mg, and Na.

13. The battery of claim 1 , wherein the oxidizing gas comprises at least one of oxygen, air, nitric oxide, and nitrogen dioxide.

14. The battery of claim 1 , wherein the solvent comprises at least one of valeronitrile, nonanenitrile, hexanenitrile, acetonitrile, propionitrile, glutaronitrile, methoxyacetonitrile, methoxybenzonitrile, methoxypropionitrile, methylglutaronitrile, butoxypropionitrile, and butoxybenzonitrile.

15. The battery of claim 1 , wherein the metal halide comprises an electrolyte salt that dissociates into a respective halide ion and a respective metal ion in the solvent, and wherein the halide ion comprises an ion of at least one of I, Br, Cl, and F, and the metal ion comprises an ion of at least one of Li, Mg, and Na.

16. The battery of claim 1 , wherein the solvent comprises an organic solvent selected from the group consisting of an ether, a glyme, a carbonate, a nitrile, an amide, an amine, an organosulfur solvent, an organophosphorus solvent, an organosilicon solvent, a fluorinated solvent, and mixtures and combinations thereof.

17. The battery of claim 1 , comprising a second cathode material in addition to the metal halide that functions as the active cathode material.

18. A method of forming the battery of claim 1 , comprising:

dissolving a metal halide in a solvent comprising a nitrile to form a solution;

soaking a separator with the solution;

stacking an anode, the separator soaked with the solution, and a current collector, wherein the stacking comprises placing the separator between the anode and the current collector; and

introducing an oxidizing gas to the stacked anode, separator, and current collector to form the battery.

19. The battery of claim 1 , wherein the battery does not include a dedicated cathode material.

20. The battery of claim 1 , wherein the metal halide receives, stores, and releases metal ions during charging and discharging of the battery and the current collector collects electrons during discharge of the battery.