Sodium borohydride fuel cells

Fuel cells utilizing the direct and indirect oxidation of borohydride ions have been described. Direct borohydride fuel cells are inherently more efficient than IBFCs; the DBFCs can produce energy densities comparable to those of methanol and oxygen–hydrogen fuel cells. The DBFC still presents a number of technical challenges such as borohydride ion crossover and the need for more selective anode materials and improved anionic membranes. The IBFCs use the well-studied MEA that is fed with high-purity hydrogen produced from the efficient hydrolysis of sodium borohydride. The main problems in this cell are removal of borohydride oxidation products, reuse of catalyst, and heat and water management