Presentation Information
[9a-P01-7]Protic ionic liquid incorporated sulfonated PVDF composite membranes for high-temperature fuel cell applications
〇(DC)Gagan Kumar Bhatt1, Chinnasamy Sengottaiyan1, Kanishka De Silva1, Masanori Hara1, Masamichi Yoshimura1 (1.Toyota Tech. Inst.)
Keywords:
Fuel cells,Proton Exchange Membrane
Membranes with high proton conductivity (PC) and good thermal stability are highly desirable for developing cost-effective fuel cells. Since proton transport relies on the availability of water molecules which begin to evaporate above 100 °C, a significant drop in PC is observed above 100 °C. To overcome this limitation, we propose to incorporate protic ionic liquid (PIL) with a melting point of ~200 °C in sulfonated polyvinylidene fluoride (SPVDF)1 polymer, enabling proton transport at higher temperatures (>100 °C) via the vehicular mechanism of proton conduction independent of water molecules. A series of membranes were prepared corresponding to different weight percentages of PIL (5% - 30%) in SPVDF. Briefly, PIL and SPVDF are mixed in dimethylformamide (DMF), followed by the solution casting and drying in a vacuum oven2. Figure 1(a) shows the measured proton conductivity at different temperatures for the fabricated membrane. It is observed that the membrane with 20 wt.% of PIL incorporated into SPVDF demonstrated around a 5-fold increase in proton conductivity (3.6 mS/cm at 110 °C) compared to the lower wt.% of PIL incorporated in SPVDF. We analyzed the thermal stability of the membranes using TGA-DTA measurements and observed that all the membranes exhibit good thermal stability (~240 °C), as shown in Fig. 1(b). The enhanced performance of membranes at elevated temperatures, combined with good thermal stability, makes them a competitive alternative for use as a polymer electrolyte membrane (PEM) in fuel cells.