  Rechargeable redox flow batteries with serpentine flow field designs have
been demonstrated to deliver higher current density and power density in medium
and large-scale stationary energy storage applications. Nevertheless, the
fundamental mechanisms involved with improved current density in flow batteries
with flow field designs have not been understood. Here we report a maximum
current density concept associated with stoichiometric availability of
electrolyte reactant flow penetration through the porous electrode that can be
achieved in a flow battery system with a "zero-gap"serpentine flow field
architecture. This concept can explain a higher current density achieved within
allowing reactions of all species soluble in the electrolyte. Further
validations with experimental data are confirmed by an example of a vanadium
flow battery with a serpentine flow structure over carbon paper electrode.
