Patent ID: 8916281

Claim:
A flow battery system comprising: a first rebalance reaction cell comprising: a first liquid half-cell chamber in fluid communication with a first source of a positive liquid electrolyte, a second liquid half-cell chamber in fluid communication with a second source of a liquid mediator electrolyte comprising dissolved ferrous iron (Fe 2+ ) ions, and a separator membrane between the first half-cell chamber and the second half-cell chamber; a second rebalance reaction cell comprising a replenishable source of metallic iron and in fluid communication with the second source of liquid mediator electrolyte; and a flow battery reaction cell coupled to the first rebalance reaction cell, the flow battery reaction cell comprising: a first liquid filled half-cell chamber of the flow battery reaction cell in fluid communication with the first source of positive liquid electrolyte and the first liquid filled half-cell chamber of the first rebalance reaction cell; and a second liquid filled half-cell chamber of the flow battery reaction cell in fluid communication with a source of negative liquid electrolyte, wherein the source of negative electrolyte is separate from the second source of liquid mediator electrolyte and the second rebalance reaction cell.