Systems and methods for rebalancing redox flow battery electrolytes
AssigneeEnerVault Corporation
InventorsAi Quoc Pham, On Kok Chang
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Abstract
Various methods of rebalancing electrolytes in a redox flow battery system include various systems using a catalyzed hydrogen rebalance cell configured to minimize the risk of dissolved catalyst negatively affecting flow battery performance. Some systems described herein reduce the chance of catalyst contamination of RFB electrolytes by employing a mediator solution to eliminate direct contact between the catalyzed membrane and the RFB electrolyte. Other methods use a rebalance cell chemistry that maintains the catalyzed electrode at a potential low enough to prevent the catalyst from dissolving.
Claims9
A method of rebalancing Fe/Cr redox flow battery electrolytes, the method comprising:
- directing a negative electrolyte solution containing Cr3+ ions and Cr2+ ions through a cathode chamber of a first rebalance cell, the cathode chamber having a first electrode;
- directing a quantity of hydrogen gas through an anode chamber of the first rebalance cell, the anode chamber having a second electrode and being separated from the cathode chamber by a separator membrane having a catalyst-containing coating on a surface facing the anode chamber;
- applying an electric current to the first rebalance cell;
- and
- controlling the quantity of hydrogen gas and the electric current applied to the first rebalance cell so as to reduce at least some of the Cr3+ ions to Cr2+ ions according to a controlled reaction rate for a controlled period of time to rebalance the negative electrolyte solution.
Dependencies are inferred from the claim text.