The direct borohydride fuel cell

The direct borohydride fuel cell (DBFC) is fed by a sodium borohydride (NaBH4) aqueous alkaline solution and can be seen as the last-born of the fuel cells. This article proposes firstly a general idea of both fuel characteristics and fuel cell fondamentals. Then the current state-of-the-art of R&D is briefly reviewed. Endly, it discusses the main issues obstructing its market competitiveness. Compared to the polymer exchange membrane fuel cell H-2/O-2 and the direct methanol fuel cell, the DBFC is superior. Its main advantages are that both fuel and cell reaction products are environmentally acceptable, safe and easily transported, and that both theoretical energy density and energy conversion efficiency are better. The DBFC is highly considered as a potential candidate for portable applications. However, many key issues have to be overcome, that is the first challenge. The second is the high price of the fuel, that presents a serious brake to its competitiveness. Furthermore, the use of platinum as catalyst contributes to this technology high cost. The research in DBFC is at the early beginning and there are real opportunities for improvements.