Current status and progress of direct borohydride fuel cell technology development

In this review article, recent advances in the development of the direct borohydride fuel cell (DBFC) technology are reviewed. Based on the reported results, it is concluded that the BH4- electro-oxidation is determined by the catalyst used and BH4- concentration at the catalytic sites. Hydrogen evolution during the DBFC operation can be suppressed by: (I) using a composite catalyst or a hydrogen storage alloy as the anode catalyst via a quasi 8-electron reaction; (2) using metals with high hydrogen over-potential, such as Au and Ag as the anode catalyst via an intrinsic 8-electron reaction; and/or (3) modifying and optimizing fuel composition. The single cell and stack performance of DBFC is mainly influenced by the hydrogen evolution, the BH4- cross-over, and the BH4- tolerance of cathode catalyst. The development of non-platinum cathode catalysts and stacking technology is on the way. The reported results are encouraging but some problems still remain to be further investigated and solved. (C) 2008 Elsevier B.V. All rights reserved.