Cost-efficient high energy density redox flow battery

Patent metadata

Field	Value
Publication number	US-12283730-B2
Application number	US-202117229719-A
Country	US
Kind code	B2
Filing date	Apr 13, 2021
Priority date	Aug 10, 2018
Publication date	Apr 22, 2025
Grant date	Apr 22, 2025

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

The invention claimed is:

1. A redox flow battery system, comprising:
a battery cell with a positive electrolyte and a negative electrolyte, the positive electrolyte in contact with a positive electrode and the negative electrolyte in contact with a negative electrode; and
a plating additive added in a millimolar concentration to the negative electrolyte, the plating additive interacting with cations of the negative electrolyte and forming complexes that plate onto the negative electrode in self-assembled monolayers, wherein the plating additive is chemically bonded to a metal plated at the negative electrode, wherein the plating additive is chemically bonded as hydrocarbon layers, wherein the self-assembled monolayers include layers of the plating additive separated by layers of the cations, and wherein the metal plated at the negative electrode is thicker than metal plated without the plating additive,
wherein in the presence of the plating additive, a plating rate of the metal onto the negative electrode is greater than when the additive is absent from the redox flow battery, and wherein the plating rate remains greater than when the additive is absent even when a temperature of the redox flow battery system is below a threshold temperature, the threshold temperature being an ambient temperature.

2. The redox flow battery system of claim 1 , wherein in the presence of the plating additive, a uniformity of a coating formed by the plating of the metal onto the negative electrode is increased relative to when the additive is absent from the redox flow battery.

3. The redox flow battery system of claim 2 , wherein in the presence of the plating additive, a presence of cracks in the coating is reduced relative to when the additive is absent from the redox flow battery.

4. The redox flow battery system of claim 1 , wherein the plating additive has a functional end group at a first end that binds to the metal and a trailing, chemically inert tail at a second end that extends away from the metal.

5. The redox flow battery system of claim 4 , wherein the metal, chemically bound by the plating additive, plates onto the negative electrode as a stack of evenly spaced apart monolayers of the metal that are separated by layers formed of the trailing, chemically inert tail of the plating additive.

6. The redox flow battery system of claim 5 , wherein the plating additive includes a fatty acid with an electron-rich functional end group and a long-chain carbon tail.

7. The redox flow battery system of claim 6 , wherein the plated metal is configured to coat the negative electrode with a thickness between several mm to over 1 cm.

8. An iron redox flow battery comprising:
an electrolyte of a battery cell formed from iron chloride complexes in aqueous solution, including a positive electrolyte in contact with a positive electrode and a negative electrolyte in contact with a negative electrode; and
a chemical substance added to the negative electrolyte at a millimolar concentration that chemically bonds with iron centers from the iron chloride complexes at a first end of the chemical substance and forms a coating around each of the iron centers, wherein the coating is formed from an inert tail at a second end of the chemical substance, the coating remaining chemically bonded to plated iron at the negative electrode, wherein the coating forms self-assembled monolayers of the iron centers separated by the inert tail, and wherein the iron centers form a plating layer of increased thickness compared to iron centers without the coating,
wherein in the presence of the chemical substance, a plating rate of the iron centers onto the negative electrode is greater than when the chemical substance is absent from the redox flow battery, and wherein the plating rate remains greater than when the chemical substance is absent even when a temperature of the iron redox flow battery is below a threshold temperature, the threshold temperature being an ambient temperature.

9. The iron redox flow battery of claim 8 , wherein the inert tail of the chemical substance is a carbon chain and wherein the coating surrounding each of the iron centers spaces the iron centers at uniform distances from one another.

10. The iron redox flow battery of claim 8 , wherein the chemical substance is stearic acid.

11. The redox flow battery system of claim 1 , further comprising a membrane separator arranged between the negative electrolyte and the positive electrolyte, the membrane separator formed from an anion exchange membrane configured to maintain a charge balance of the battery cell and increase an energy density of the redox flow battery system.

12. The iron redox flow battery of claim 8 , further comprising an anion exchange membrane separator positioned between the positive electrode and the negative electrode, and in contact with the electrolyte, the anion exchange membrane separator configured to selectively allow transport of ions across the anion exchange membrane separator.

Assignees

• Ess Technology Inc

Inventors

• Song Yang

Classifications

• H01M8/1018

  Polymeric electrolyte materials · CPC title

• H01M8/02

  Details (electrodes H01M4/86 - H01M4/98) · CPC title

• H01M4/368

  Liquid depolarisers · CPC title

• H01M4/582

  Halogenides · CPC title

• Y02E60/50

  Fuel cells · CPC title