NOVEL ALUMINUM BATTERIES - A STEP TOWARDS DERIVATION OF SUPERBATTERIES

In alkaline-elevated temperature electrolytes, planar aluminum is capa ble of supporting current densities one to two orders of magnitude hig her than conventional electrodes. Conditions are investigated in which these unusually high power densities, through the electrolyte-surface interface, may also occur with high coulombic efficiency, a step towa rds the derivation of superbatteries. Aluminum-ferricyanide batteries based on aqueous solution phase alkaline ferricyanide cathodes and sol id aluminum anodes are investigated. The battery is expressed by alumi num oxidation and ferricyanide reduction for an overall battery discha rge consisting of: Al + 3OH(-) + 3Fe(CN)(6)(3-)-->Al(OH)(3) + 3Fe(CN)( 6)(4-); E-cell =2.8 V. Aluminum potassium ferricyanide batteries are d emonstrated with current densities approaching 2000 mA/cm(2) with pola rization losses of 0.6 mV/cm(2)/mA, resulting in a high power density of over 2 W/cm(2). (C) 1998 Elsevier Science B.V.