Direct borohydride/peroxide fuel cells using Prussian Blue cathodes

Direct borohydride fuel cells (DBFCs) are receiving much attention during the last decade. Many researchers are now focused on DBFCs operating on sodium borohydride (NaBH 4) as the fuel and hydrogen peroxide (H 2O 2) as the oxidant. In the present work, direct NaBH 4/H 2O 2 fuel cells consisting of platinum (Pt) anodes, a Prussian Blue (PB)-coated Pt or a Pt cathode, and a Nafion N117 membrane as the separator, are assembled. The effect of different operational conditions, namely the fuel (NaBH 4 + NaOH) and oxidant (H 2O 2 + HCl) compositions, as well as the operation temperature, on the performance of these DBFCs is investigated. The obtained results are evaluated and the most suitable conditions for the operation of these NaBH 4/H 2O 2 systems are proposed. The use of the PB-coated electrode can lead to up to a 50% increase in the peak power density, as compared to the cell using a single Pt cathode. At 65 °C, the DBFC using the PB-modified electrode attained over 200 mW cm -2, at a cell voltage of 0.8 V.