A NOVEL AQUEOUS ALUMINUM FERRICYANIDE BATTERY

Aluminum ferricyanide batteries based on aqueous solution-phase alkaline ferricyanide cathodes and solid aluminum anodes are introduced and investigated. The battery is expressed by aluminum oxidation and ferricyanide reduction for an overall battery discharge consisting of Al + 3 OH- + 3Fe(CN)63- --> Al(OH)3 + 3Fe(CN)64- E(cell) = 2.8 V First generation aluminum potassium ferricyanide batteries are demonstrated with an open-circuit voltage of 2.2 V. This system produces current densities approaching 2000 MA/cm2 with polarization losses of 0.6 MV CM2 mA-1, resulting in a high power density of over 2 W/cm2, moderate energy densities of 96 Wh/kg, and coulombic efficiencies of aluminum and ferricyanide discharge in excess of 80%.