Alkaline manganese redox flow battery with inhibitor

Patent metadata

Field	Value
Publication number	US-2022376286-A1
Application number	US-202117326518-A
Country	US
Kind code	A1
Filing date	May 21, 2021
Priority date	May 21, 2021
Publication date	Nov 24, 2022
Grant date	—

Abstract

A redox flow battery includes a redox flow cell and a supply and storage system external of the redox flow cell. The supply and storage system includes first and second electrolytes for circulation through the redox flow cell. The first electrolyte is a liquid electrolyte having electrochemically active manganese species with multiple, reversible oxidation states in the redox flow cell. The electrochemically active manganese species may undergo reactions that cause precipitation of manganese oxide solids. The first electrolyte includes an inhibitor that limits the self-discharge reactions. The inhibitor includes an oxoanion compound.

First claim

What is claimed is:

1 . A redox flow battery comprising:
a redox flow cell; a supply and storage system external of the redox flow cell, the supply and storage system including first and second electrolytes for circulation through the redox flow cell, the first electrolyte is a liquid electrolyte having electrochemically active manganese species with multiple, reversible oxidation states in the redox flow cell, wherein the electrochemically active manganese species can undergo reactions that cause precipitation of manganese oxide solids; and the first electrolyte further including an inhibitor limiting the self-discharge reactions, the inhibitor including an oxoanion compound.

2 . The redox flow battery as recited in claim 1 , wherein the inhibitor is selected from the group consisting of phosphates (PO 4 3− ), nitrates (NO 3 − ), and sulfates (SO 4 2− ), or any compound that decomposes in the electrolytes to form phosphate, nitrate, or sulfate species, and mixtures thereof.

3 . The redox flow battery as recited in claim 2 , wherein the inhibitor is selected from the group consisting of phosphates and mixtures thereof.

4 . The redox flow battery as recited in claim 2 , wherein the inhibitor is selected from the group consisting of nitrates and mixtures thereof.

5 . The redox flow battery as recited in claim 2 , wherein the inhibitor is selected from the group consisting of sulfates, and mixtures thereof.

6 . The redox flow battery as recited in claim 2 , wherein the inhibitor is a compound that decomposes during operation of the redox flow battery to generate phosphate, nitrate, or sulfate species in solution.

7 . The redox flow battery as recited in claim 2 , wherein the first electrolyte has a composition in which there is from 0.0001 mol to 0.1 mol of inhibitor per 1 mol of manganese ions.

8 . The redox flow battery as recited in claim 7 , wherein the first electrolyte has a composition in which there is from 0.001 mol to 0.01 mol of inhibitor per 1 mol of manganate.

9 . The redox flow battery as recited in claim 1 , wherein the electrochemically active manganese species are MnO 4 − and MnO 4 2− .

10 . An electrolyte for a redox flow battery, comprising:
a supporting electrolyte including a solvent and a supporting salt; electrochemically active manganese species dissolved in the supporting electrolyte, the electrochemically active manganese species having multiple, reversible oxidation states in the supporting electrolyte; and an inhibitor dissolved in the supporting electrolyte and limiting reactions of the electrochemically active manganese species that cause precipitation of manganese oxide solids, the inhibitor including an oxoanion compound.

11 . The electrolyte as recited in claim 10 , wherein the inhibitor is selected from the group consisting of phosphates (PO 4 3− ), nitrates (NO 3 − ), and sulfates (SO 4 2− ), or any compound that decomposes in the electrolytes to form phosphate, nitrate, or sulfate species, and mixtures thereof.

12 . The electrolyte as recited in claim 11 , wherein the inhibitor is selected from the group consisting of phosphates and mixtures thereof.

13 . The electrolyte as recited in claim 11 , wherein the inhibitor is selected from the group consisting of nitrates and mixtures thereof.

14 . The electrolyte as recited in claim 11 , wherein the inhibitor is selected from the group consisting of sulfates and mixtures thereof.

15 . The electrolyte as recited in claim 11 , wherein the inhibitor is a compound that decomposes in the electrolyte to generate phosphate, nitrate, or sulfate species in solution.

16 . The electrolyte as recited in claim 11 having a composition in which there is from 0.0001 mol to 0.1 mol of inhibitor per 1 mol of manganate.

17 . The electrolyte as recited in claim 11 , wherein the electrochemically active manganese species are MnO 4 − and MnO 4 2− .

Assignees

• Raytheon Tech Corp

Inventors

• Davenport Timothy
• Saraidaridis James D
• Darling Robert Mason

Classifications

• Y02E60/50

  Fuel cells · CPC title

• H01M8/188 Primary

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

• H01M2300/0014

  Alkaline electrolytes · CPC title

• H01M8/04186

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

• H01M8/04201

  Reactant storage and supply, e.g. means for feeding, pipes · CPC title