Electrochemical energy storage systems and methods featuring optimal membrane systems

Patent metadata

Field	Value
Publication number	US-9865893-B2
Application number	US-201313949530-A
Country	US
Kind code	B2
Filing date	Jul 24, 2013
Priority date	Jul 27, 2012
Publication date	Jan 9, 2018
Grant date	Jan 9, 2018

Abstract

This invention is directed to aqueous redox flow batteries comprising ionically charged redox active materials and separators, wherein the separator is about 100 microns or less and the flow battery is capable of (a) operating with a current efficiency of at least 85% with a current density of at least about 100 mA/cm 2 ; (b) operating with a round trip voltage efficiency of at least 60% with a current density of at least about 100 mA/cm 2 ; and/or (c) giving rise to diffusion rates through the separator for the first active material, the second active material, or both, of about 1×10 −7 mol/cm 2 -sec or less.

First claim

What is claimed:

1. A flow battery, comprising:
a first electrolyte comprising an aqueous solution comprising a first active material and at least one mobile ion;
a second electrolyte comprising an aqueous solution comprising a second active material and at least one mobile ion;
wherein at least one of the first active material and the second active material comprises a metal ligand coordination compound comprising a chelating organic ligand and the metal ligand coordination compound bears a negative ionic charge;
the first electrolyte is substantially free of the second active material and the second electrolyte is substantially free of the first active material;
a first electrode in contact with said first electrolyte;
a second electrode in contact with said second electrolyte; and
a separator;
wherein the flow battery is capable of operating with a current efficiency of at least 85% with a current density of at least about 100 mA/cm 2 and wherein the separator has a thickness of about 100 microns or less,
wherein the separator comprises a porous membrane having pores with an average size distribution of between about 0.001 nm and 100 nm, and
wherein the at least one of the first active material and the second active material have an average diameter that is about 50% greater than an average pore size of the porous membrane.

2. The flow battery of claim 1 , wherein diffusive crossover of active materials represents 2% or less current efficiency loss during charge or discharge.

3. The flow battery of claim 1 , wherein electrical shorts account for less than or equal to 2% current efficiency loss during charge or discharge.

4. The flow battery of claim 1 , wherein transference of active materials represents 2% or less current efficiency loss during charge or discharge.

5. The flow battery of claim 1 , wherein an amount of current that is diverted to parasitic reactions represents 4% or less current efficiency loss during charge or discharge.

6. The flow battery of claim 1 , wherein shunt currents within fluidic manifolds represent 5% or less current efficiency loss during charge or discharge.

7. The flow battery of claim 1 , wherein the first and second active materials are first and second metal ligand coordination compounds, the first metal ligand coordination compound comprising a first metal and a first ligand and the second metal ligand coordination compound comprising a second metal and a second ligand, at least one of the first ligand and the second ligand being a chelating organic ligand and at least one of the first metal ligand coordination compound and the second metal ligand coordination compound bearing a negative ionic charge.

8. The flow battery of claim 7 , wherein the first and second ligands comprise one or more of the following: CN − , H 2 O, halo, hydroxyl, amines, polyamines, polyalcohols, anions of carboxylic acids, dicarboxylic acids, polycarboxylic acids, amino acids, carbonyl or carbon monoxide, nitride, oxo, sulfide, pyridine, pyrazine, amido groups, imido groups, alkoxy groups, siloxy, thiolate, catechol, pyrogallate, bipyridine, bipyrazine, ethylenediamine, diols, terpyridine, diethylenetriamine, triazacyclononane, trisaminomethane, quinones, hydroquinones, viologens, pyridinium, acridinium, polycyclic aromatic hydrocarbons or combinations thereof.

9. The flow battery of claim 7 , wherein the first metal comprises one or more of the following atoms: Al, Ca, Co, Cr, Cu, Fe, Mg, Mn, Mo, Ni, Pd, Pt, Ru, Sn, Ti, V, Zn, Zr, or a combination thereof.

10. The flow battery of claim 7 , wherein the second metal comprises one or more of the following atoms: Al, Ca, Co, Cr, Cu, Fe, Mg, Mn, Mo, Ni, Pd, Pt, Ru, Sn, Ti, V, Zn, Zr, or a combination thereof.

11. The flow battery of claim 7 , wherein the first metal and the second metal compound differ in reduction potential by at least about 0.5 volts.

12. The flow battery of claim 7 , wherein the first metal and the second metal differ in reduction potential by at least about 1.0 volt.

13. The flow battery of claim 7 , wherein the first metal is the same as the second metal; and wherein the first metal and the second metal have different oxidation states.

14. The flow battery of claim 1 , wherein the second active material is different from the first active material.

15. The flow battery of claim 1 , wherein the mobile ion carries at least about 80% of the ionic current during charge/discharge.

16. The flow battery of claim 1 , wherein the mobile ion carries at least about 85% of the ionic current during charge/discharge.

17. The flow battery of claim 1 , wherein the mobile ion comprises one or more of the following: Li + , K + , Na + , Mg 2+ , Ca 2+ , Sr 2+ , Cl − , Br − , I − , OH − or a combination thereof.

18. The flow battery of claim 1 , wherein the separator has a thickness of 50 microns or less and the flow battery operates with at least about 98% current efficiency.

19. The flow battery of claim 1 , wherein the separator has a thickness of 25 microns or less and the flow battery operates with at least about 96% current efficiency.

20. The flow battery of claim 1 , wherein the flow battery is capable of operating with shorting losses of about 1 mA/cm 2 or less.

21. The flow battery of claim 1 , wherein the separator comprises a polymer, wherein the polymer is a cationic exchange membrane comprised of anionic functional groups.

22. The flow battery of claim 21 , wherein the polymer comprises one or more of the following: a cross-linked halogenated alkylated compound with a polyamine, a cross-linked aromatic polysulfone type polymer with a polyamine, perfluorinated hydrocarbon sulfonate ionomers, sulfonated polyetherether ketone (sPEEK), sulfonated poly(phthalazinone ether ketone), sulfonated phenolphthalein poly(ether sulfone), sulfonated polyimides, sulfonated polyphosphazene, sulfonated polybenzimidazole, aromatic polymers containing a sulfonic acid group, sulfonated perfluorinated polymer, fluorinated ionomers with sulfonate groups, carboxylate groups, phosphate groups, boronate acid groups, or combinations thereof, polyaromatic ethers with sulfonate or carboxylate groups, poly(4-vinyl pyridine), poly(2-vinyl pyridine), poly(styrene-b-2-vinylpyridine), poly(vinyl pyrrolidine), poly(1-methyl-4-vinylpyridine), poly[(2,2′-m-phenylene)-5,5′-bibenzimidazole][poly(2,2′-(m-phenylene)-5,5′-bibenzimidazole], poly(2,5-benzimidazole), polyacrylate, polymethacrylate or combinations thereof.

23. The flow battery of claim 1 , wherein the separator comprises a solid polymer, wherein the solid polymer is an anionic exchange membrane comprised of cationic functional groups.

24. The flow battery of claim 23 , wherein the polymer comprises one or more of the following: polydiaryldimethylammonium, poly(methacryloyloxyethyltriethylammonium), poly(diallylammonium), or combinations thereof.

25. The flow battery of claim 1 , wherein the separator comprises a polymer and the polymer comprises one or more of the following: polytetrafluoroethylene, polyvinyl, polystyrene, polyethylene, polypropylene, polyesters, perfluorinated polymers, polyvinylidene fluoride, poly(ether-ketone-ether-ketone-ketone), poly(vinyl chloride), substituted vinyl polymers, polystyrene, or combinations thereof.

26. The flow battery of claim 25 , wherein the separator comprises a membrane further comprising a reinforcement material.

27. The flow battery of

Assignees

• Lockheed Martin Advanced Energy Storage Llc

Inventors

• Esswein Arthur J
• Reece Steven Y
• Madden Thomas H
• Jarvi Thomas D
• Goeltz John
• Amadeo Desiree
• King Evan R
• Tyagi Nitin

Classifications

• H01M50/497

  Ionic conductivity · CPC title

• H01M50/491

  Porosity · CPC title

• H01M50/489

  Separators, membranes, diaphragms or spacing elements inside the cells, characterised by their physical properties, e.g. swelling degree, hydrophilicity or shut down properties · CPC title

• H01M8/20

  Indirect fuel cells, e.g. fuel cells with redox couple being irreversible (H01M8/18 takes precedence) · CPC title

• H01M2008/1095

  Fuel cells with polymeric electrolytes · CPC title