The need for energy storage is growing to reduce the carbon footprint of electricity

production. Among the conceivable storage solutions, the redox flow battery (RFB) is

one of the most promising. The best-researched type is the vanadium flow battery, but

extensive research is underway to develop a cheaper and more compact system. The full-

iron redox flow battery is an attractive alternative. A testing module has been developed,

in order to study the influence of different operating parameters on the system output.

The experiments highlight that the electrode compression, the stacking of single cells and

the charge and discharge rates are design key factors and need a precise optimization. A

35% electrode compression is a good trade-off between pump power losses and low contact

resistances inside the cell. Single cells undergo a higher self-discharge when they are piled

up; it is the direct effect of a power leakage called shunt current. The stack design must

be thought with caution to lessen this power loss. The cycling profile also influence the

battery performance. The findings confirm that optimizing the charge and discharge rates

can prolong the system lifespan.