The Study Of The Conductivity Property Of The CsHSO₄Doping Al₂O₃and The Primary Investigation Of The Cell Performance Of Its Proton Exchange Membrane

In this thesis, different methods were used to synthesis composite protonconductors. Meanwhile, the effect of methods on the proton conductivity of thecomposite proton conductors was studied. PVDF was chosen as the backing materialand the ratio of PVDF to composite proton conductors was changed. Finally, theMEA were hot-pressed under different parameter. The performance of the MEAwere tested to discover the optimal producing parameters. The main discoveries wereas follows:(1) CsHSO4reacted with mesoporous alumina under melting method; Grinding,Ball-milling, and Ball-milling with ethanol can keep the CsHSO4and mesoporousalumina from reacting. However, mechanical friction destroyed part of themesoporous of the alumina, resulting in the decreasing of SBETin varying degrees.Among them, the Ball-milling with ethanol got the best performance and the largestSBET. The proton conductivity of the mesoporous alumina decreased with increasingthe temperature; On the contrary, the proton conductivity of the composite protonconductors increased with increasing the temperature. The conductivity ofmesoporous alumina was improved significantly with adding CsHSO4. Thecomposite proton conductors synthesized by Balling-milling with ethanolapproached the best performance in conductivity.(2) At the temperature range of100-200℃, the proton conductivity of thePVDF membrane and composite proton exchange membranes increased with thetemperature. The proton conductivity of the composite proton exchange membraneswere2-4orders higher than that of the PVDF membrane at the same temperature.The weight ratio of the PVDF of the composite membranes should be higher than20%, which makes the membrane more resilient. The proton conductivity of thecomposite proton exchange membranes increased with the ratio of CsHSO4when theweight ratio of the CsHSO4was larger than50%. Among the composite proton exchange membranes in which the ratio of PVDF beyond20%, the#7compositemembrane got the best performane.(3) Compared with brush painting, spray method produced a better catalystlayer, in which catalyst distributed evenly. The main effort of temperature, time,and pressure of hot-pressing concentrated on forming of proton channel andthe integrity of the membrane. The parameter of hot-pressing progress of thebest MEA was as follows:145℃,8MPa,10s. The performance of MEAwhich tested at the low and media temperature range showed the possibleapplication of this kind of MEA in PEMCF. Comparation betweenNafion-MEA and composite MEA indicated that the letter has longer cyclelife.