ELECTROLYTE FOR REDOX FLOW BATTERY AND REDOX FLOW BATTERY INCLUDING THE SAME

• US 20130004819A1
• Filed: 02/16/2012
• Published: 01/03/2013
• Est. Priority Date: 06/28/2011
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd., Seoul National University R&DB Foundation (Seoul National University)
• Original Assignee: Samsung Electronics Co. Ltd., Seoul National University R&DB Foundation (Seoul National University)
• Inventors: Hwang, Seung-sik, Lee, Doo-yeon, Kim, Hyung-tae, Mun, Jun-young, Kim, Young-gyu, Kwon, Oh-min, Yim, Tae-eun
• Granted Patent: US 8,927,130 B2
• Time in Patent Office: Days
• US Class Current: 429/106
• CPC Class Codes: H01M 2300/0025 Organic electrolyte
• CPC Class Codes: H01M 2300/0082 Organic polymers
• CPC Class Codes: H01M 8/188 by recharging of redox couples containing fluids; Redox flow type batteries
• CPC Class Codes: Y02E 60/50 Fuel cells

Abstract

An electrolyte for a redox flow battery and a redox flow battery including the electrolyte, the electrolyte including a metal-ligand coordination compound as a cation and an anion containing at least four atoms linked to each other by a straight chain in a certain direction.

Claims

1. An electrolyte for a redox flow battery, the electrolyte comprising:

a non-aqueous solvent;

a supporting electrolyte; and

a metal salt,

wherein the metal salt comprises a metal-ligand coordination compound as a cation and an anion containing at least four atoms linked to each other by a straight chain in a certain direction.

2. The electrolyte of claim 1, wherein the anion comprises at least 8 atoms.

3. The electrolyte of claim 1, wherein the anion has a maximum diameter in the range of about 6 Å

to about 12 Å

.

4. The electrolyte of claim 1, wherein the anion is at least one of the anions represented by Formulae 1 through 4 below:

5. The electrolyte of claim 1, wherein the anion comprises at least one selected from the group consisting of

6. The electrolyte of claim 1, wherein the metal in the metal-ligand coordination compound comprises at least one selected from the group consisting of nickel (Ni), cobalt (Co), iron (Fe), ruthenium (Ru), zinc (Zn), manganese (Mn), yttrium (Y), zirconium (Zr), titanium (Ti), chromium (Cr), magnesium (Mg), cerium (Ce), copper (Cu), lead (Pb), and vanadium (V).

7. The electrolyte of claim 1, wherein the ligand in the metal-ligand coordination compound comprises at least one selected from the group consisting of dipyridyl, terpyridyl, phenanthroline, acetylacetonate, ethylenediamine, propylenediamine, and N-heterocyclic carbene (NHC).

8. The electrolyte of claim 7, wherein the N-heterocyclic carbene (NHC) comprises at least one selected from the group consisting of 2,6-bis(methylimidazole-2-ylidene)pyridine, 1,3-dimesitylimidazole, 1,3-bis(2,5-diisopropylphenyl)imidazole, 1,3-dimethylimidazole, 1,3-di-tert-butylimidazole, 1,3-dicyclohexylimidazole, and 1-ethyl-3-methylimidazole.

9. The electrolyte of claim 1, wherein the metal-ligand coordination compound comprises at least one of the following cations:

10. The electrolyte of claim 1, wherein the metal-ligand coordination compound undergoes a reversible oxidation/reduction reaction.

11. The electrolyte of claim 1, wherein the metal salt comprises

12. The electrolyte of claim 1, wherein the metal salt has a concentration in the range of about 1.2 M to about 5.0 M.

13. The electrolyte of claim 1, wherein the non-aqueous solvent comprises at least one selected from the group consisting of diethyl carbonate, dimethyl carbonate, acetonitrile, γ

-butyrolactone (GBL), propylene carbonate (PC), ethylene carbonate (EC), N-methyl-2-pyrrolidone (NMP), fluoroethylene carbonate, and N,N-dimethylacetamide.

14. The electrolyte of claim 1, wherein the supporting electrolyte comprises at least one selected from the group consisting of LiBF₄, LiPF₆, LiClO₄, LiCF₃SO₃, Li(CF₃SO₂)₂N, tetraethylammonium tetrafluoroborate (TEABF₄), tetrabutylammonium tetrafluoroborate (TBABF₄), NaBF₄, NaPF₆, potassium bis(fluorosulfonyl)imide, methanesulfonyl chloride, and (NH₄)₂SO₄.

15. A redox flow battery comprising:

a cathode cell comprising a cathode and a catholyte;

an anode cell comprising an anode and an anolyte; and

an ion exchange membrane disposed between the cathode cell and the anode cell,

wherein at least one of the catholyte and the anolyte comprises the electrolyte of claim 1.

16. The redox flow battery of claim 15, further comprising a catholyte tank and an anolyte tank respectively connected to the cathode cell and the anode cell to transfer fluid.

17. The redox flow battery of claim 15, wherein the ion exchange membrane is an anion exchange membrane.

18. The redox flow battery of claim 17, wherein the anion exchange membrane is an anion exchange membrane obtained by aminating a copolymer of styrene-divinylbenzene used as a base by introducing a chloromethyl group, an anion exchange membrane obtained by substituting a copolymer of vinylpyridine-divinyl benzene with quaternary pyridium, or an anion exchange membrane obtained by aminating an aromatic polysulfone copolymer used as a base by introducing a chloromethyl group.