Highly stable phenazine derivatives for aqueous redox flow batteries

Patent metadata

Field	Value
Publication number	US-10454124-B2
Application number	US-201715625750-A
Country	US
Kind code	B2
Filing date	Jun 16, 2017
Priority date	Jun 16, 2017
Publication date	Oct 22, 2019
Grant date	Oct 22, 2019

Abstract

Embodiments of an aqueous electrolyte comprising a base and a phenazine derivative are disclosed. Redox flow batteries including the aqueous electrolyte are also disclosed. The phenazine derivative has a chemical structure according to formula I:

First claim

We claim:

1. An aqueous electrolyte, comprising:
water; and
a phenazine derivative according to formula I or a salt thereof, where formula I is

wherein each R 1 independently is —H, —OCH 3 , —R a SO 3 H, —R a COOH, —R a SO 3 M, —R a COOM, —R a NR 3 3 X, —R a NR 3 2 , —R a PO(OH) 2 , —R a SH, —R a PS(OH) 2 , —R a —O—PO(OH) 2 , —R a —O—PS(OH) 2 , —R a —S—PS(OH) 2 , or —(OCH 2 CH 2 ) n OR 3 ,
each R 2 independently is —H or —R a OH, wherein at least one R 2 is other than hydrogen,
each R 3 independently is H or C 1 -C 5 alkyl,
each R a independently is absent or C 1 -C 5 alkyl,
M is a cation,
X is an anion,
n is an integer ≥1, and
y+z=1, 2, 3, 4, 5, 6, 7, or 8, where y is 0, 1, 2, 3, or 4 and z is 1,2, 3, or 4,
wherein the aqueous electrolyte does not include any electrochemically active component other than the phenazine derivative.

2. The aqueous electrolyte of claim 1 , wherein:
y is 0, 1, or 2;
z is 1 or 2; and
y+z=2, 3, or 4.

3. The aqueous electrolyte of claim 1 , wherein:
each R 1 independently is —SO 3 H, —COOH, or —OCH 3 ; and
each R 2 is —OH.

4. The aqueous electrolyte of claim 1 , further comprising a base.

5. The aqueous electrolyte of claim 1 , further comprising an acid.

6. The aqueous electrolyte of claim 1 , wherein the electrolyte has an average pH within a range of 6.5 to 7.5, the electrolyte further comprising at least one aqueous-soluble neutral salt other than a phenazine derivative salt.

7. The aqueous electrolyte of claim 1 , wherein the phenazine derivative has a structure according to formula II

wherein each R 1 independently is —H, —OCH 3 , —R a SO 3 H, —R a COOH, —R a SO 3 M, —R a COOM, —R a NR 3 3 X, —R a NR 3 2 , —R a PO(OH) 2 , —R a SH, —R a PS(OH) 2 , —R a —O—PO(OH) 2 , —R a —O—PS(OH) 2 , —R a —S—PS(OH) 2 , or —(OCH 2 CH 2 ) n OR 3 ,
each R 2 independently is —H or —R a OH, wherein at least one R 2 is other than hydrogen;
each R 3 independently is H or C 1 -C 5 alkyl;
each R a independently is absent or C 1 -C 5 alkyl;
M is a cation;
X is an anion; and
n is an integer ≥1.

8. The aqueous electrolyte of claim 7 , wherein:
each R 1 independently is —H, —SO 3 H, —COOH, or —OCH 3 ; and
each R 2 independently is —H or —OH, wherein at least one R 2 is —OH.

9. The aqueous electrolyte of claim 1 , wherein the phenazine derivative is:

or any combination thereof.

10. The aqueous electrolyte of claim 1 , wherein the aqueous electrolyte further comprises an alkali metal hydroxide.

11. The aqueous electrolyte of claim 1 , wherein the phenazine derivative is

12. The aqueous electrolyte of claim 1 , consisting essentially of:
a base;
the phenazine derivative; and
water.

13. The aqueous electrolyte of claim 1 , where the phenazine derivative is present in the electrolyte at a concentration within a range of from 0.01 M to 8 M.

14. An aqueous electrolyte system for use in a redox flow battery system, comprising:
an aqueous anolyte comprising the aqueous electrolyte according to claim 1 ; and
an aqueous catholyte comprising an electrochemically active material.

15. The aqueous electrolyte system of claim 14 , wherein the aqueous catholyte further comprises a base or an acid.

16. The aqueous electrolyte system of claim 14 , wherein the electrochemically active material of the aqueous catholyte comprises K 4 Fe(CN) 6 , K 3 Fe(CN) 6 , or a combination thereof.

17. The aqueous electrolyte system of claim 14 , wherein:
the aqueous anolyte comprises an alkali metal base, and

or any combination thereof; and
the aqueous catholyte comprises an alkali metal base and K 4 Fe(CN) 6 , K 3 Fe(CN) 6 , or a combination thereof.

18. The aqueous electrolyte system of claim 14 , wherein:
the aqueous anolyte comprises an alkali metal base and

 and
the aqueous catholyte comprises the alkali metal base and K 4 Fe(CN) 6 , K 3 Fe(CN) 6 , or a combination thereof.

19. A redox flow battery system, comprising:
the aqueous electrolyte system of claim 14 ; and
a separator.

20. The redox flow battery system of claim 19 , further comprising a carbon-based anode and a carbon-based cathode.

Assignees

• Battelle Memorial Institute

Inventors

• Wei Xiaoliang
• Wang Wei
• Hollas Aaron M
• Sprenkle Vincent L
• Nie Zimin
• Li Bin

Classifications

• H01M4/96

  Carbon-based electrodes · CPC title

• H01M2300/0002

  Aqueous electrolytes · CPC title

• H01M8/188 Primary

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

• H01M4/9016

  Oxides, hydroxides or oxygenated metallic salts · CPC title

• H01M4/90

  Selection of catalytic material · CPC title