Membrane-less hybrid flow battery based on low-cost elements

The capital cost of conventional redox flow batteries is relatively high (>USD$ 200/kWh) due to the use of expensive active materials and ion-exchange membranes. This paper presents a membrane-less hybrid organic-inorganic flow battery based on the low-cost elements zinc (92.7% with the use of carbon felt electrodes. In the presence of a fully oxidized active species close to its solubility limit, dissolution of the deposited anode is relatively slow (<2.37 g h−1 cm−2) with an equivalent corrosion current density of <1.9 mA cm−2. In a parallel plate flow configuration, the resulting battery was charge-discharge cycled at 30 mA cm−2 with average coulombic and energy efficiencies of c.a. 71.8 and c.a. 42.0% over 20 cycles, respectively.