Flow battery electrolyte compositions containing an organosulfate wetting agent and flow batteries including same
A stabilized electrolyte for a metal-halogen flow battery and flow battery system including the same. The electrolyte includes an aqueous metal halide, an anionic wetting agent, a bromine complexing agent, and bromine.
1. A flow battery system, comprising:
a stack of flow battery cells that do not contain a separator in reaction zones formed between anode and cathode electrodes of each flow battery cell;
a reservoir connected to the reaction zones of the stack; and
an electrolyte disposed in the reservoir, the electrolyte comprising:
aqueous ZnBr 2 or aqueous ZnBr 2 and ZnCl 2 ;
bromine;
a bromine complexing agent;
an anti-dendrite agent;
a chelating agent; and
sodium dodecyl sulfate (SDS) at a concentration ranging from about 2 mM to about 35 mM,
wherein:
the electrolyte maintains a pH of from about 1.5 to about 3, after 50 charge and discharge cycles; and
the electrolyte does not comprise a pH stabilizer.
2. The system of claim 1 , wherein the electrolyte comprises the ZnBr 2 or ZnBr 2 and ZnCl 2 , at a concentration of about 1.5 M to 2.5 M.
3. The system of claim 1 , wherein the electrolyte comprises:
the ZnBr 2 at a concentration ranging from about 1.25 M to about 2.0 M; and
the ZnCl 2 at a concentration ranging from about 0.2 M to about 0.5 M.
4. The system of claim 1 , wherein the bromine complexing agent comprises at least one of a morpholinium, pyrrolidinium, imidazolium, picolinium or pyridinium salt, and a quaternary ammonium bromide (QBr).
5. The system of claim 4 , wherein the electrolyte comprises the bromine complexing agent at a concentration of from 0.75 M to about 1.25 M.
6. The system of claim 1 , wherein the anti-dendrite agent comprises one or more of Bi, Pb, Th, Ti, and Se.
7. The system of claim 1 , wherein the anti-dendrite agent comprises PbBr 2 at a concentration of from about 0.1 mM to about 0.35 mM.
8. The system of claim 1 , wherein the chelating agent comprises ethylenediaminetetraacetic acid (EDTA).
9. The system of claim 8 , wherein the electrolyte comprises the EDTA at a concentration of from about 2 mM to about 4 mM.
10. The system of claim 1 , wherein:
the bromine comprises Br 2 ; and
the electrolyte comprises the Br 2 at a concentration of from 0.3 M to about 0.7 M.
11. The system of claim 1 , wherein:
the bromine complexing agent comprises at least one of a morpholinium, pyrrolidinium, imidazolium, picolinium or pyridinium salt, and a quaternary ammonium bromide (QBr); and
the anti-dendrite agent comprises one or more of Bi, Pb, Th, Ti, and Se.
12. The system of claim 11 , wherein the electrolyte comprises:
the SDS at a concentration ranging from about 8 mM to about 12 mM;
the ZnBr 2 at a concentration ranging from about 1.25 M to about 2.0 M;
the ZnCl 2 at a concentration ranging from about 0.2 M to about 0.5 M;
QBr as the bromine complexing agent, at a concentration of from 0.75 M to about 1.25 M;
EDTA as the chelating agent, at a concentration of from about 2 mM to about 4 mM;
PbBr 2 as the anti-dendrite agent, at a concentration of from about 0.1 mM to about 0.35 mM; and
Br 2 as the bromine, at a concentration of from 0.3 M to about 0.7 M.