Negative electrode electrolyte solution and flow battery

Patent metadata

Field	Value
Publication number	US-2018261871-A1
Application number	US-201815900500-A
Country	US
Kind code	A1
Filing date	Feb 20, 2018
Priority date	Mar 10, 2017
Publication date	Sep 13, 2018
Grant date	—

Abstract

A negative electrode electrolyte solution which contains titanium ions, a chelating agent, and a catechol-based compound having a catechol structure is used for a negative electrode of a flow battery in which an electrolyte solution is circulated so as to perform charge and discharge.

First claim

What is claimed is:

1 . A negative electrode electrolyte solution that is used for a negative electrode of a flow battery in which an electrolyte solution is circulated so as to perform charge and discharge, comprising titanium ions, a chelating agent, and a catechol-based compound having a catechol structure.

2 . The negative electrode electrolyte solution according to claim 1 , wherein the catechol-based compound contains at least one of pyrocatechol and catechol derivatives having at least one of a hydroxy group, a sulfo group, and a carboxy group as a substituent.

3 . The negative electrode electrolyte solution according to claim 1 , wherein the chelating agent is a compound having a diamine structure and having at least three carboxy groups in the molecule.

4 . The negative electrode electrolyte solution according to claim 3 , wherein the chelating agent is a compound having the diamine structure, the diamine structure including a carbon chain which may have a substituent and which has a carbon number of 2 or more and 5 or less and carboxy groups bonding to the nitrogen of the diamine structure.

5 . The negative electrode electrolyte solution according to claim 1 , wherein the content of the chelating agent is within the range of 1.5 molar equivalents or less relative to the titanium ions.

6 . The negative electrode electrolyte solution according to claim 1 , wherein the content of the catechol-based compound is within the range of 1.5 molar equivalents or less relative to the titanium ions.

7 . The negative electrode electrolyte solution according to claim 1 ,
wherein the catechol-based compound contains at least one of pyrocatechol, pyrogallol, 4,5-dihydroxy-1,3-benzenedisulfonic acid, and derivatives thereof, and the chelating agent contains at least one of ethylenediaminetetraacetic acid (EDTA), 1,3-diamino-2-hydroxypropanetetraacetic acid (DPTA), and derivatives thereof.

8 . The negative electrode electrolyte solution according to claim 1 , wherein the pH of the negative electrode electrolyte solution is 3 or more and 9 or less.

9 . The negative electrode electrolyte solution according claim 1 ,
wherein the catechol-based compound is an alkali metal salt, and the chelating agent is an alkali metal salt.

10 . A flow battery comprising a liquid delivery portion that enables the negative electrode electrolyte solution according to claim 1 to flow and to come into contact with a negative electrode collector.

11 . The flow battery according to claim 10 ,
wherein a solid active material is also present in a flow passage through which the negative electrode electrolyte solution is circulated, and the negative electrode electrolyte solution is a mediator-containing electrolyte solution that includes a complex serving as the mediator and containing titanium ions, the chelating agent, and the catechol-based compound.

12 . The flow battery according to claim 11 , wherein the negative electrode electrolyte solution has a low-potential-side oxidation-reduction potential lower than the oxidation-reduction potential of the solid active material and has a high-potential-side oxidation-reduction potential higher than the oxidation-reduction potential of the solid active material.

13 . The flow battery according to claim 10 , comprising:
a case; a separator that separates the inside of the case into a positive electrode chamber and a negative electrode chamber; a negative electrode collector disposed in the negative electrode chamber; and a storage portion that is disposed in a flow passage, through which the negative electrode electrolyte solution flows, and that stores the solid active material.

14 . The flow battery according to claim 11 , wherein the solid active material contains at least one of lithium titanate phosphate and sodium titanate phosphate.

Assignees

• Toyota Chuo Kenkyusho Kk

Inventors

• Sakata Jiro

Classifications

• H01M4/8663

  Selection of inactive substances as ingredients for catalytic active masses, e.g. binders, fillers · CPC title

• H01M4/90

  Selection of catalytic material · CPC title

• H01M8/188 Primary

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

• H01M2300/0005

  Acid electrolytes · CPC title

• Y02E60/50

  Fuel cells · CPC title