Abstract
A Salinity Gradient Flow Battery (SGFB) is a novel type of battery that
utilizes the selective ion-transition across ion exchange membranes to
produce Donnan potential and stores energy in the form of salinity
gradient power (SGP). Nevertheless, the commercialization of SGFB had
been halted because of the low charging-discharging efficiency due to
the relatively high ohmic solution resistance in the low salinity
solution. By considering the contribution of supporting ions in a redox
flow battery (RFB), we proposed an “Ion-plus SGFB” system by
internally-integrating the RFB and SGFB system for the breakthrough of
SGFB recycling efficiency. The supporting ions in the salinity solutions
overcome the trade-off limitation between Donnan potential and
internal-resistance without sacrificing on the SGP, and increase the
power density to 1.15 W cm-2 which is two times higher than control
system (0.45 W cm-2). The novel designed system is
environmental-friendly and gentle for ion exchange membrane