Flow battery

Patent metadata

Field	Value
Publication number	US-11374249-B2
Application number	US-201816167532-A
Country	US
Kind code	B2
Filing date	Oct 23, 2018
Priority date	Jul 19, 2016
Publication date	Jun 28, 2022
Grant date	Jun 28, 2022

Abstract

A flow battery according to one aspect of the present disclosure includes: a first liquid containing dissolved therein a charge mediator and a discharge mediator; a first electrode immersed in the first liquid; and a first active material immersed in the first liquid. The equilibrium potential of the charge mediator is lower than the equilibrium potential of the first active material, and the equilibrium potential of the discharge mediator is higher than the equilibrium potential of the first active material.

First claim

What is claimed is:

1. A flow battery comprising:
a first liquid containing dissolved therein a charge mediator and a discharge mediator;
a first electrode immersed in the first liquid;
a first active material immersed in the first liquid; and
an electrolyte salt that is dissolved in the first liquid,
wherein the equilibrium potential of the charge mediator is lower than the equilibrium potential of the first active material,
wherein the equilibrium potential of the discharge mediator is higher than the equilibrium potential of the first active material,
wherein a concentration of the electrolyte salt in the first liquid is equal to or lower than a concentration of the charge mediator in the first liquid, wherein the charge mediator is at least one selected from the group consisting of phenanthrene, o-terphenyl, triphenylene, anthracene, acenaphthene, acenaphthylene, fluoranthene, 2,2′-bipyridyl, trans-stilbene, cis-stilbene, propiophenone, butyrophenone, valerophenone, ethylenediamine, benzil, and tetraphenylcyclopentadienone, and
wherein the concentration of the charge mediator is equal to or lower than 0.1 M.

2. The flow battery according to claim 1 ,
wherein lithium is dissolved in the first liquid,
wherein the first active material is a material having the property of occluding and releasing the lithium,
wherein, during charging, the charge mediator is reduced on the first electrode, and the charge mediator reduced on the first electrode is oxidized by the first active material while the first active material occludes the lithium, and
wherein, during discharging, the first active material containing the lithium occluded therein reduces the discharge mediator and releases the lithium, and the discharge mediator reduced by the first active material is oxidized on the first electrode.

3. The flow battery according to claim 2 ,
wherein, during the charging, the discharge mediator is reduced on the first electrode, and
wherein, during the discharging, the charge mediator is oxidized on the first electrode.

4. The flow battery according to claim 1 ,
wherein the charge mediator is a condensed aromatic compound, and the discharge mediator is a condensed aromatic compound, and
wherein the first liquid containing the condensed aromatic compounds dissolved therein has the property of causing the lithium to release solvated electrons and dissolve as cations.

5. The flow battery according to claim 1 ,
wherein the concentration of the electrolyte salt in the first liquid is equal to or lower than the concentration of the discharge mediator in the first liquid.

6. The flow battery according to claim 1 , further comprising:
a second liquid;
a second electrode that serves as a counter electrode of the first electrode and is immersed in the second liquid; and
a separator that separates the first electrode and the first liquid from the second electrode and the second liquid,
wherein the electrolyte salt is dissolved in the second liquid, and the concentration of the electrolyte salt in the first liquid is lower than the concentration of the electrolyte salt in the second liquid.

7. The flow battery according to claim 1 ,
wherein the electrolyte salt is at least one selected from the group consisting of LiBF 4 , LiN(SO 2 CF 3 ) 2 , LiN(SO 2 F) 2 , and LiCF 3 SO 3 .

8. The flow battery according to claim 1 ,
wherein the electrolyte salt is LiPF 6 .

9. The flow battery according to claim 1 ,
wherein the first liquid contains at least one selected from the group consisting of tetrahydrofuran, 2-methyltetrahydrofuran, 1,2-dimethoxyethane, 2,5-dimethyltetrahydrofuran, diethoxyethane, dibutoxyethane, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, 3-methylsulfolane, and tetrahydrofurfurylamine.

10. The flow battery according to claim 1 , further comprising
a first circulator,
wherein the first circulator circulates the first liquid between the first electrode and the first active material.

11. The flow battery according to claim 10 ,
wherein the first circulator includes a first container,
wherein the first active material and the first liquid are contained in the first container,
wherein the first circulator circulates the first liquid between the first electrode and the first container, and
wherein the first active material comes into contact with the first liquid within the first container to thereby cause at least one of an oxidation reaction of the charge mediator by the first active material and a reduction reaction of the discharge mediator by the first active material to proceed.

12. The flow battery according to claim 11 ,
wherein the first circulator includes a first passage prevention member that prevents passage of the first active material, and
wherein the first passage prevention member is disposed in a channel through which the first liquid flows from the first container to the first electrode.

13. The flow battery according to claim 1 , further comprising:
a second liquid containing a second electrode-side mediator dissolved therein;
a second electrode that serves as a counter electrode of the first electrode and is immersed in the second liquid;
a second active material immersed in the second liquid; and
a separator that separates the first electrode and the first liquid from the second electrode and the second liquid,
wherein the second electrode-side mediator is oxidized and reduced on the second electrode, and
wherein the second electrode-side mediator is oxidized and reduced by the second active material.

14. The flow battery according claim 13 ,
wherein lithium is dissolved in the second liquid,
wherein the second active material is a material having the property of occluding and releasing the lithium,
wherein, during charging, the second electrode-side mediator is oxidized on the second electrode, and the second electrode-side mediator oxidized on the second electrode is reduced by the second active material while the second active material releases the lithium, and
wherein, during discharging, the second electrode-side mediator is reduced on the second electrode, and the second electrode-side mediator reduced on the second electrode is oxidized by the second active material while the second active material occludes the lithium.

15. The flow battery according to claim 13 ,
wherein the second electrode-side mediator is tetrathiafulvalene.

16. The flow battery according to claim 13 ,
wherein the second active material contains lithium iron phosphate.

17. The flow battery according to claim 13 , further comprising
a second circulator,
wherein the second circulator circulates the second liquid between the second electrode and the second active material.

18. The flow battery according to claim 17 ,
wherein the second circulator includes a second container,
wherein the second active material and the second liquid are contained in the second container,
wherein the second circulator circulates the second liquid between the second electrode and the second container, and
wherein the second active material comes into contact with the second liquid within the second container, and the second electrode-side mediator is thereby oxidized or reduced by the second active material.

19. The flow battery according to claim 18 ,
wherein the second circulator includes a second passage prevention member that prevents passage of the second active material, and
wherein the second passage prevention member is di

Assignees

• Panasonic Ip Man Co Ltd

Inventors

• Fujimoto Masahisa
• Ito Shuji

Classifications

• Y02E60/50

  Fuel cells · CPC title

• H01M8/188 Primary

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

• H01M8/023

  Porous and characterised by the material · CPC title

• H01M4/382

  Lithium (H01M4/405 takes precedence) · CPC title

• H01M8/04186

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