Cost-efficient high energy density redox flow battery

Patent metadata

Field	Value
Publication number	US-2022285717-A1
Application number	US-202217664562-A
Country	US
Kind code	A1
Filing date	May 23, 2022
Priority date	Aug 10, 2018
Publication date	Sep 8, 2022
Grant date	—

Abstract

Methods and systems are provided for a redox flow battery system. In one example, the redox flow battery is adapted with an additive included in a battery electrolyte and an anion exchange membrane separator dividing positive electrolyte from negative electrolyte. An overall system cost of the battery system may be reduced while a storage capacity, energy density and performance may be increased.

First claim

1 - 13 . (canceled)

14 . A method for a redox flow battery system comprising;
plating a metal from an electrolyte solution onto a negative electrode during charging of the redox flow battery system; deplating the metal from the negative electrode into the electrolyte solution during discharging of the redox flow battery system; and transporting anions across an anion exchange membrane separator positioned in the electrolyte solution, the anion exchange membrane separator configured to separate a negative electrode compartment from a positive electrode compartment of the redox flow battery system; wherein the electrolyte solution in the negative electrode compartment comprises stearic acid as a plating additive to form uniform and crack-free layers of metal at the negative electrode.

15 . The method of claim 14 , wherein transporting the anions across the anion exchange membrane separator includes transporting the anions without transporting cations or complexes across the separator.

16 . The method of claim 14 , wherein transporting the anions across the anion exchange membrane separator includes transporting the anions from a region of the redox flow battery system of lower overall positive bias to a region of higher overall positive bias.

17 . The method of claim 14 , wherein the electrolyte solution consists of redox active species.

18 . (canceled)

19 . (canceled)

20 . (canceled)

21 . The method of claim 14 , wherein the anion exchange membrane separator is formed from one or more of a polymer network with ion transport selectivity, a covalent organic framework, and a pre-fabricated, commercially available material.

22 . The method of claim 21 , wherein the polymer network comprises one or more of heteroaromatic compounds, aniline, olefins, and sulfones.

23 . The method of claim 14 , wherein the anion exchange membrane separator is fabricated by one of grafting, surface coating, solvent, casting, and conformal coating.

24 . The method of claim 14 , wherein transporting the anions across the anion exchange membrane separator comprises transporting Cl − while inhibiting transport of iron cations.

25 . The method of claim 14 , wherein transporting the anions across the anion exchange membrane separator comprises transporting Cl − while inhibiting transport of the stearic acid.

26 . The method of claim 14 , wherein discharging the redox flow battery system comprises providing up to 100 hours of energy to power an external system.

27 . The method of claim 14 , wherein iron cations of the metal, bound by the stearic acid, plate onto the negative electrode as a stack of evenly spaced apart monolayers of iron that are separated by layers formed of the trailing, chemically inert tail of the stearic acid.

28 . The method of claim 27 , wherein the iron cations comprise divalent and trivalent iron.

29 . The method of claim 14 , wherein the crack-free and uniform layers of metal at the negative electrode are self-assembled monolayers of iron, the iron bound by the stearic acid.

30 . The method of claim 14 , wherein a free energy of the metal is lowered when bound by the stearic acid and the lowering of the free energy causes the metal to self-assembly into layers separated by the stearic acid.

31 . The method of claim 14 , wherein the crack-free and uniform layers of metal have a thickness of over 1 cm.

32 . The method of claim 14 , wherein more than one molecule of the stearic acid bonds with each metal center of the crack-free and uniform layers of metal.

33 . The method of claim 14 , wherein the anion exchange membrane separator comprises pH resistant functional groups.

Assignees

• Ess Technology Inc

Inventors

• Song Yang
• Evans Craig E

Classifications

• H01M8/04186

  of liquid-charged or electrolyte-charged reactants · CPC title

• H01M8/188 Primary

  by recharging of redox couples containing fluids; Redox flow type batteries · CPC title

• H01M2300/0002

  Aqueous electrolytes · CPC title

• H01M2300/0082

  Organic polymers · CPC title

• H01M4/368

  Liquid depolarisers · CPC title