Electrode compositions and related energy storage devices

Patent metadata

Field	Value
Publication number	US-9748564-B2
Application number	US-201414550408-A
Country	US
Kind code	B2
Filing date	Nov 21, 2014
Priority date	Nov 21, 2014
Publication date	Aug 29, 2017
Grant date	Aug 29, 2017

Abstract

A positive electrode composition is presented. The composition includes granules that comprise an electroactive metal, an alkali metal halide, and a metal sulfide composition that is substantially-free of oxygen. A molar ratio of the electroactive metal to an amount of sulfur in the metal sulfide composition is between about 1.5:1 and about 50:1. The positive electrode composition is substantially free of iron oxide, iron sulfate, cobalt oxide and cobalt sulfate. An energy storage device and a related energy storage system are also described.

First claim

The invention claimed is:

1. A positive electrode composition comprising granules that themselves comprise:
an electroactive metal that comprises nickel;
an alkali metal halide, and
a metal sulfide composition that is substantially free of oxygen, wherein a molar ratio of the nickel to an amount of sulfur in the metal sulfide composition in the granules is in a range of from 2:1 to 10:1,
wherein the positive electrode composition is substantially free of iron oxide, iron sulfate, cobalt oxide, and cobalt sulfate.

2. The positive electrode composition of claim 1 , wherein the alkali metal halide comprises at least one halide of sodium, potassium, or lithium.

3. The positive electrode composition of claim 1 , wherein the metal sulfide composition is M x S y , where M is selected from iron or cobalt; and the ratio of x to y is between about 0.5:1 and about 1.5:1.

4. The positive electrode composition of claim 3 , wherein the metal sulfide composition M x S y is selected from FeS, FeS 2 , CoS 2 , or Co 3 S 4 .

5. The positive electrode composition of claim 3 , wherein the metal sulfide composition M x S y is FeS.

6. The positive electrode composition of claim 1 , further comprising an electrolyte salt that comprises a complex metal halide, wherein the electrolyte salt has a melting temperature in a range from about 150 degrees Celsius to about 300 degrees Celsius.

7. The positive electrode composition of claim 6 , wherein the electrolyte salt is sodium tetrachloroaluminate (NaAlCl 4 ).

8. The positive electrode composition of claim 1 , wherein
the alkali metal halide comprises one or more of sodium chloride, sodium fluoride, sodium iodide, and sodium bromide; and
the metal sulfide composition comprises iron sulfide (FeS).

9. An energy storage device comprising a first compartment comprising an alkali metal, a second compartment comprising a positive electrode composition, and a solid separator capable of transporting alkali metal ions between the first compartment and the second compartment, wherein the positive electrode composition comprises:
(a) an electrolyte salt comprising a complex metal halide; and
(b) granules that themselves comprise:
(i) an electroactive metal that comprises nickel;
(ii) an alkali metal halide; and
(iii) a metal sulfide composition that is substantially free of oxygen, wherein a molar ratio of nickel to an amount of sulfur in the metal sulfide composition in the granules is in a range of from 2:1 to 10:1, and
wherein the positive electrode composition is substantially free of iron oxide, iron sulfate, cobalt oxide, and cobalt sulfate.

10. The energy storage device of claim 9 , wherein the alkali metal comprises sodium, potassium or lithium.

11. The energy storage device of claim 9 , wherein the first compartment comprises molten sodium.

12. The energy storage device of claim 9 , wherein the electrolyte salt is sodium tetrachloro aluminate (NaAlCl 4 ).

13. An energy storage system comprising a plurality of the energy storage devices of claim 9 .

14. The positive electrode composition of claim 1 , wherein a molar ratio of a total amount of an alkali metal in the alkali metal halide to the amount of sulfur in the metal sulfide composition is between about 1.75:1 and about 10:1.

15. The positive electrode composition of claim 1 , wherein the electroactive metal comprises iron, cobalt or combination thereof.

Assignees

• Gen Electric

Inventors

• Hart Richard Louis
• Vallance Michael Alan

Classifications

• H01M4/38 Primary

  of elements or alloys · CPC title

• H01M10/399

  Cells with molten salts · CPC title

• H01M2300/0054

  Halogenides · CPC title

• H01M4/136

  Electrodes based on inorganic compounds other than oxides or hydroxides, e.g. sulfides, selenides, tellurides, halogenides or LiCoFy · CPC title

• H01M4/5815

  Sulfides · CPC title