Additives for a flow battery

Patent metadata

Field	Value
Publication number	US-11394069-B2
Application number	US-201615773670-A
Country	US
Kind code	B2
Filing date	Nov 7, 2016
Priority date	Nov 10, 2015
Publication date	Jul 19, 2022
Grant date	Jul 19, 2022

Abstract

The invention relates to an electrolyte solution suitable for use in a zinc-bromine battery, comprising zinc bromide and a mixture of at least two complexing agents selected from the group consisting of 1-R 2 -2-methyl pyridinium bromide and 1-R 3 -3-methyl pyridinium bromide salts, wherein each of R 2 and R 3 is independently an alkyl group having not less than five carbon atoms.

First claim

The invention claimed is:

1. An electrolyte solution suitable for use in a zinc-bromine battery, comprising zinc bromide and a mixture of at least two complexing agents selected from the group consisting of 1-R 2 -2-methyl pyridinium bromide and 1-R 3 -3-methyl pyridinium bromide salts, wherein each of R 2 and R 3 is independently an alkyl group having not less than five carbon atoms.

2. The electrolyte solution according to claim 1 , wherein R 2 and R 3 are independently selected from the group consisting of C5, C7 and C8 straight-chain and branched alkyl groups.

3. The electrolyte solution according to claim 2 , wherein at least one of R 2 and R 3 is C5 alkyl group.

4. The electrolyte solution according to claim 1 , wherein the mixture comprises two complexing agents selected from the group consisting of 1-R 2 -2-methyl pyridinium bromide and 1-R 3 -3-methyl pyridinium bromide salts, wherein the molar ratio between the components of the mixture is in the range from 1:5 to 5:1.

5. The electrolyte solution according to claim 3 , comprising 1-n-pentyl-2-methyl pyridinium bromide (2-MPePy) and 1-n-pentyl-3-methyl pyridinium bromide (3-MPePy).

6. The electrolyte solution according to claim 3 , comprising 1-n-pentyl-2-methyl pyridinium bromide (2-MPePy) and 1-isopentyl-3-methyl pyridinium bromide (3-MiPePy).

7. The electrolyte solution according to claim 3 , comprising 1-n-pentyl-3-methyl pyridinium bromide (3-MPePy) and 1-isopentyl-3-methyl pyridinium bromide (3-MiPePy).

8. The electrolyte solution according to claim 1 , which further comprises tetraalkyl ammonium halide salt.

9. The electrolyte solution according to claim 8 , comprising 1-R 2 -2-methyl pyridinium bromide, 1-R 3 -3-methyl pyridinium bromide and a tetraalkyl ammonium halide salt.

10. The electrolyte solution according to claim 9 , wherein R 2 is C5 straight or branched alkyl; R 3 is C7-C8 straight or branched alkyl; and the tetraalkyl ammonium salt is selected from the group consisting of tetraethyl ammonium bromide and tetrabutyl ammonium bromide.

11. The electrolyte solution according to claim 10 , comprising 1-n-pentyl-2-methyl pyridinium bromide, 1-iso-octyl-3-methyl pyridinium bromide and tetraethyl ammonium bromide.

12. The electrolyte solution according to claim 8 , comprising a first 1-R 3 -3-methyl pyridinium bromide, a second 1-R 3 -3-methyl pyridinium bromide and a tetraalkyl ammonium salt.

13. The electrolyte solution according to claim 12 , wherein the first R 3 is C5 straight or branched alkyl and the second R 3 is C7-C8 straight or branched alkyl.

14. The electrolyte solution according to claim 13 , comprising 1-n-pentyl-3-methyl pyridinium bromide, 1-iso-octyl-3-methyl pyridinium bromide and tetrabutyl ammonium bromide.

15. A method of using a mixture comprising at least two complexing agents selected from the group consisting of 1-R 2 -2-methyl pyridinium bromide and 1-R 3 -3-methyl pyridinium bromide salts, wherein each of R 2 and R 3 is independently an alkyl group having not less than five carbon atoms, said method comprising adding the mixture as an additive to the electrolyte solution of zinc bromine flow cells operating at a temperature above 35° C.

16. The method according to claim 15 , wherein R 2 and R 3 are independently selected from the group consisting of C5, C7 and C8 normal and branched alkyl groups.

17. A method of operating a zinc-bromine battery, comprising adding to the electrolyte of said battery a mixture of at least two complexing agents selected from the group consisting of 1-R 2 -2-methyl pyridinium bromide and 1-R 3 -3-methyl pyridinium bromide salts, wherein each of R 2 and R 3 is independently an alkyl group having not less than five carbon atoms, and charging or discharging said cell at a temperature above 35° C.

18. The method according to claim 17 , wherein R 2 and R 3 are independently selected from the group consisting of C5, C7 and C8 normal and branched alkyl groups.

Assignees

• Bromine Compounds Ltd

Inventors

• Magnes Ben-Zion
• Cohen Neta
• Ben-David Iris
• Costi Ronny

Classifications

• H01M4/86

  Inert electrodes with catalytic activity, e.g. for fuel cells · CPC title

• H01M2300/0002

  Aqueous electrolytes · CPC title

• Y02E60/10

  Energy storage using batteries · CPC title

• H01M8/188

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

• H01M12/085 Primary

  Zinc-halogen cells or batteries · CPC title