A modular arrangement of cells that enables adjustments in cell currents in response to changes in concentration of the redox reactants. The adjustments improve battery efficiency by more closely matching the current in a given cell to the rate at which reactants are supplied to that cell. The cell modules provide the flexibility to operate flow batteries efficiently over a wide range of electrolyte states of charge and allow managed scale-up while easing manufacturability concerns.
STATEMENT OF FEDERALLY FUNDED RESEARCH
 Inventions included in this patent application were made with Government support under DE-OE0000225 "Recovery Act--Flow Battery Solution for Smart Grid Renewable Energy Applications" awarded by the US Department of Energy (DOE). The Government has certain rights in these inventions.