Negative electrode catalyst for the iron chromium REDOX energy storage system
AssigneeThe United States of America as represented by the Administrator of the National Aeronautics and Space Administration
InventorsRandall F. Gahn, Norman H. Hagedorn
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Abstract
A REDOX cell to operate at elevated temperatures and utilizing the same two metal couples in each of the two reactant fluids is disclosed. Each fluid includes a bismuth salt and may also include a lead salt. A low cost, cation permselective membrane separates the reactant fluids.
Claims20
A REDOX system comprising:
- a cell having first and second chambers separated by a cation permeable membrane;
- a first electrically conductive, electrode disposed in said first chamber;
- a second electrically conductive electrode disposed in said second chamber;
- a first reactant fluid including iron chloride, chromium chloride and bismuth nitrate in an aqueous HCl solution, said first and second electrodes being inert to the reactant fluid and;
- a second reactant fluid including iron chloride, chromium chloride and bismuth nitrate in an aqueous HCl solution, said first and second electrodes being inert to the reactant fluid;
- means for directing said first and second reactant fluids through said first and second chambers, respectively, whereby a difference in electrical potential applied between said first and second electrodes causes bismuth to plate onto the most negative electrode.
A method of operating a REDOX cell of the type having first and second chambers separated by a cation permeable membrane and having first and second carbon electrodes disposed in said first and second chambers, respectively, comprising the steps of:
- directing through said first chamber a first reactant fluid comprised of an aqueous HCl solution having dissolved therein iron chloride, chromium chloride and bismuth nitrate;
- directing through said second chamber a second reactant fluid comprised of an aqueous HCl solution having dissolved therein iron chloride, chromium chloride and bismuth nitrate;
- and
- applying an electric potential between said first and second electrodes to charge said cell and to deposit a layer of bismuth on the electrode which is at negative electric potential.
A REDOX electrical cell comprising:
- a container having first and second chambers formed by a cation permeable membrane;
- first and second electrically conductive electrodes disposed in said first chamber and said second chamber, respectively, said first electrode being coated with bismuth;
- a first reactant fluid in said first chamber said first reactant fluid being an aqueous HCl solution containing iron chloride, Cr.sup.+2 ions and nitrate ions;
- and
- a second reactant fluid in said second chamber said second reactant fluid being an aqueous HCl solution containing bismuth nitrate, chromium chloride, and Fe.sup.+3 ions, said first electrode being electrically negative with respect to said second electrode.
Dependencies are inferred from the claim text.