Abstract: A method and a system for using flow cell batteries with mixed Fe/V electrolytes are provided. An exemplary method includes flowing an anolyte through a first channel in an electrochemical cell, wherein the first channel is formed in the space between an anode current collector and an ion exchange membrane. A catholyte is flowed through a second channel in the electrochemical cell, wherein the second channel is formed in the space between a cathode current collector and the ion exchange membrane, wherein the first channel and the second channel are separated by an ion exchange membrane, and wherein the catholyte includes a mixed electrolyte including both iron and vanadium ions. Ions are flowed through the ion exchange membrane to oxidize the anolyte and reduce the catholyte. An electric current is generated between the anode current collector and the cathode current collector.

Abstract: An electrolyte, a method for making the electrolyte, and a flow cell battery are provided. The electrolyte includes about 1.0 molar (M) to about 1.5 M iron ions and about 1.0 M to about 1.5 M vanadium ions.

Abstract: A method and a system for using flow cell batteries with mixed Fe/V electrolytes are provided. An exemplary method includes flowing an anolyte through a first channel in an electrochemical cell, wherein the first channel is formed in the space between an anode current collector and an ion exchange membrane. A catholyte is flowed through a second channel in the electrochemical cell, wherein the second channel is formed in the space between a cathode current collector and the ion exchange membrane, wherein the first channel and the second channel are separated by an ion exchange membrane, and wherein the catholyte includes a mixed electrolyte including both iron and vanadium ions. Ions are flowed through the ion exchange membrane to oxidize the anolyte and reduce the catholyte. An electric current is generated between the anode current collector and the cathode current collector.

Abstract: In one embodiment of the present disclosure, a composition for producing a vanadium electrolyte includes a vanadium compound and an ion solution containing vanadium ions and hydrogen ions. In another embodiment, a method for producing a vanadium electrolyte includes obtaining a vanadium compound, and mixing the vanadium compound with an ion solution containing vanadium ions and hydrogen ions.

Abstract: In one embodiment, a redox flow battery includes an electrochemical cell in fluid communication with anolyte and catholyte working electrolytes, and a primary OCV cell to measure the potential difference between the positive and negative working electrolyte, and a reference OCV cell to measure the potential difference between the reference cell working electrolyte, which is one of the anolyte and catholyte working electrolytes, and a reference electrolyte, wherein the reference electrolyte has a known potential. In another embodiment, a method of operating a redox flow battery includes calculating the potential values of the anolyte and catholyte working electrolytes based on the known potential values of the reference electrolyte and the first and second potential difference values obtained from the primary OCV cell and the reference OCV cell.

Abstract: In one embodiment, a cell in a redox flow battery includes a first flow frame for flow of a catholyte, a second flow frame for flow of an anolyte, and a separator between the first flow frame and the second flow frame, wherein the separator has a first side and a second side and an outer perimeter, and a gasket-and-separator assembly including a gasket assembly laminated to the separator, wherein the gasket assembly seals the outer perimeter of the separator on the first side and the second side.

Abstract: Methods of determining concentrations and/or amounts of redox-active elements at each valence state in an electrolyte solution of a redox flow battery are provided. Once determined, the concentrations and/or amounts of the redox-active elements at each valence state can be used to determine side-reactions, make chemical adjustments, periodically monitor battery capacity, adjust performance, or to otherwise determine a baseline concentration of the redox-active ions for any purpose.

Abstract: Methods of determining concentrations and/or amounts of redox-active elements at each valence state in an electrolyte solution of a redox flow battery are provided. Once determined, the concentrations and/or amounts of the redox-active elements at each valence state can be used to determine side-reactions, make chemical adjustments, periodically monitor battery capacity, adjust performance, or to otherwise determine a baseline concentration of the redox-active ions for any purpose.