LAUSR

Abstract A direct borohydride fuel cell (DBFC) is a type of low temperature fuel cell, and to commercialize this type of fuel cell, it requires efficient and inexpensive proton exchange membranes. In this study, a binary polymer blend is formulated from inexpensive and ecofriendly polymers such as iota carrageenan (IC) and polyvinyl alcohol (PVA). Zirconiam phosphate (ZrPO4) was synthesized from a simple impregnation — calcination method and later embedded as a doping agent into the polymeric matrix with percentage (1–7.5) wt.%. The novel nanocomposite membranes were evaluated by TGA, DSC, FTIR, XRD and SEM. The oxidative stability and tensile strength of the obtained membranes were enhanced and achieved results better than those of Nafion117 due to an increase in the number of hydrogen bonds formed between the polymer functional groups and oxygen functional groups of ZrPO4with increasing doping concentration. In addition, the borohydride permeability of the membranes decreased with increasing ZrPO4weight percentage, while the ionic conductivity and power density increased to 25.5 mS cm−1 and 66 mW cm−2, respectively, for membrane with 5 wt.% of ZrPO4. The fabricated membrane with the optimum properties (PVA/IC/ZrPO4− 5) can be efficient as a proton exchange membrane towards the development of green and low cost DBFCs.