Promising TiOSO₄ Composite Polybenzimidazole‐Based Membranes for High Temperature PEMFCs

Abstract

Composite membranes were prepared from poly[2,2'-(m-phenylene)-5,5'-bibenzimidazole] (polybenzimidazole: PBI), and titanium oxysulfate (TiOSO₄) with the aim of using these systems as electrolytes in high temperature proton exchange membrane fuel cells (PEMFCs). The presence of TiOSO₄ was confirmed by using Fourier-transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD) analyses. Energy-dispersive X-ray spectroscopy (EDS) mapping of titanium and sulphur revealed that the titanium salt was homogenously distributed on the surface of the membrane. The presence of the titanium salt did not change the thermal behaviour of the doped membranes. The composite membrane was used as an electrolyte in an actual fuel cell operating at 150 °C. The cell showed a lower performance than a cell operated with the standard PBI membrane, but this was attributable to the electrodes rather than the membrane. The most remarkable result was that the fuel cell operating with the composite membrane showed the best stability during the preliminary long-term test because of the better acid retention capability of these titanium-based materials.

Enhancement of high temperature PEMFC stability using catalysts based on Pt supported on SiC based materials

“…Thus, peaks at 2 values of 39.6 • , 46.1 • , 67.4 • which corresponding to Pt (111), Pt (200) and Pt (220) planes, respectively are observed in both samples. The platinum peaks are [20,21]. Table 1 shows the Pt crystallite size on the two supports.…”

Experimental Study and Comparison of Various Designs of Gas Flow Fields to PEM Fuel Cells and Cell Stack Performance

“…Ferng et al (2008) did experimental tests on PEM fuel cell and reported similar results. Lobato et al (2010Lobato et al ( , 2011 had conduct experimental tests to compared four types of flow field designs -serpentine, parallel, pin, and interdigitated -and they found serpentine had the highest output power of all. Jang et al (2008) numerically compared the performance of PEM fuel cell with four-channel serpentine, the so called Z-type flow field and parallel channel flow field, and they found that a cell with four-channel serpentine flow field showed the best performance.…”

Catalyst, Membrane, Free Electrolyte Challenges, and Pathways to Resolutions in High Temperature Polymer Electrolyte Membrane Fuel Cells

“…This is done to avoid the high acid loadings required to achieve reasonable conductivity which can cause mechanical stability issues with the PBI membranes [66][67][68]. An avenue to avoid this issue currently being researched involves filling the membrane with solid proton conductors such as solid acids, ionic liquids, and graphite [50,[69][70][71][72][73][74][75][76][77][78] or hygroscopic materials [79][80][81][82].…”