Borohydride electro-oxidation in a molten alkali hydroxide eutectic mixture and a novel borohydride-periodate battery

The electrochemical oxidation of BH4(-) in a molten NaOH-KOH eutectic mixture (0.515:0.485 mole fractions), is investigated for the first time by cyclic voltammetry and electrochemical impedance spectroscopy. Anodically oxidized Ni is electrocatalytically more active than Pt for BHT oxidation in the molten alkali electrolyte as shown by the more than three times higher exchange current density (i.e. 15.8 mA cm(-2) vs. 4.6 mA cm-2 at 185 degrees C). Next the proof-of-concept for a novel BH4(-)/IO4(-) molten alkali electrolyte battery is presented. Using oxidized Ni mesh anode and Pt mesh cathode a maximum power density of 63 mW cm(-2) is achieved at 185 degrees C. 2015 Elsevier B.V. All rights reserved.