The Effect of Sulfated Zirconia and Zirconium Phosphate Nanocomposite Membranes on Fuel-Cell Efficiency

To investigate the effect of acidic nanoparticles on proton conductivity, permeability, and fuel-cell performance, a commercial Nafion® 117 membrane was impregnated with zirconium phosphates (ZrP) and sulfated zirconium (S-ZrO2) nanoparticles. As they are more stable than other solid superacids, sulfated metal oxides have been the subject of intensive research. Meanwhile, hydrophilic, proton-conducting inorganic acids such as zirconium phosphate (ZrP) have been used to modify the Nafion® membrane due to their hydrophilic nature, proton-conducting material, very low toxicity, low cost, and stability in a hydrogen/oxygen atmosphere. A tensile test, water uptake, methanol crossover, Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermal gravimetric analysis (TGA), and scanning electron microscopy (SEM) were used to assess the capacity of nanocomposite membranes to function in a fuel cell. The modified Nafion® membrane had a higher water uptake and a lower water content angle than the commercial Nafion® 117 membrane, indicating that it has a greater impact on conductivity. Under strain rates of 40, 30, and 20 mm/min, the nanocomposite membranes demonstrated more stable thermal deterioration and higher mechanical strength, which offers tremendous promise for fuel-cell applications. When compared to 0.113 S/cm and 0.013 S/cm, respectively, of commercial Nafion® 117 and Nafion® ZrP membranes, the modified Nafion® membrane with ammonia sulphate acid had the highest proton conductivity of 7.891 S/cm. When tested using a direct single-cell methanol fuel cell, it also had the highest power density of 183 mW cm−2 which is better than commercial Nafion® 117 and Nafion® ZrP membranes.

The efficiency of chitosan-graphene oxide composite membranes modified with genipin in fuel cell application

The paper reports on the processing of chitosan N-doped reduced graphene oxide (CS/N-rGO) nanocomposite membranes prepared by a facile, dispersion-casting procedure aimed as anion exchange membranes in fuel cells. Genipin (GEN) was used as a crosslinking agent to ameliorate mechanical weakens of nanocomposite membranes, while the N-rGO filler, aside of its role as a mechanical enhancer, is expected to improve the ionic conductivity of membranes. The resulting properties of processed membranes in terms of morphology, tensile strength, elasticity, and ethanol permeability were examined. The relevance of the membranes in terms of efficiency and performance was demonstrated in a single cell test.