Highly stable phenazine derivatives for aqueous redox flow batteries

Patent metadata

Field	Value
Publication number	US-2018366757-A1
Application number	US-201715625750-A
Country	US
Kind code	A1
Filing date	Jun 16, 2017
Priority date	Jun 16, 2017
Publication date	Dec 20, 2018
Grant date	—

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:
a phenazine derivative according to formula I or a salt thereof, where formula I is

wherein R 1 and R 2 independently are —H, —R a OR 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 , wherein at least one R 1 or 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 and z independently are 0, 1, 2, 3, or 4.

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 —OH, —SO 3 H, —COOH, —OCH 3 , or —CH 2 N(CH 3 ) 3 X; and each R 2 independently is —OH, —SO 3 M, or —CH 2 N(CH 3 ) 3 X.

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

8 . The aqueous electrolyte of claim 7 , wherein each R 1 and R 2 independently is —H, —OH, —SO 3 H, —COOH, —OCH 3 , —SO 3 M, or —CH 2 N(CH 3 ) 3 X.

9 . The aqueous electrolyte of claim 7 , wherein:
each R 1 independently is —H, —OH, —SO 3 H, —COOH, —OCH 3 , or —CH 2 N(CH 3 ) 3 X; and each R 2 independently is —H, —OH, —SO 3 M, or —CH 2 N(CH 3 ) 3 X.

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

or any combination thereof.

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

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

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

14 . 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.

15 . 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.

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

17 . The aqueous electrolyte system of claim 15 , wherein the electrochemically active material of the aqueous catholyte comprises K 4 Fe(CN) 6 , K 3 Fe(CN) 6 , or a combination thereof.

18 . The aqueous electrolyte system of claim 15 , 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.

19 . The aqueous electrolyte system of claim 15 , 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.

20 . A redox flow battery system, comprising:
the aqueous electrolyte system of claim 15 ; and a separator.

21 . The redox flow battery system of claim 20 , 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

• H01M4/9016

  Oxides, hydroxides or oxygenated metallic salts · CPC title

• C07D241/46

  Phenazines · CPC title

• H01M2300/0002

  Aqueous electrolytes · CPC title

• H01M8/188 Primary

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