Nafion^® based hybrid composite membrane containing GO and dihydrogen phosphate functionalized ionic liquid for high temperature polymer electrolyte membrane fuel cell

다국어 초록 (Multilingual Abstract)

<P><B>Abstract</B></P> <P>A new hybrid composite proton exchange membrane has been synthesized from dihydrogen phosphate functionalized imidazolium ionic liquid (IL-H<SUB>2</SUB>PO<SUB>4</SUB>), graphene oxide, and Nafion 117 solution. The chemical structure and thermal stability of the dihydrogen phosphate functionalized imidazolium ionic liquid (IL-H<SUB>2</SUB>PO<SUB>4</SUB>) have been analyzed by <SUP>1</SUP>H nuclear magnetic resonance (NMR) spectroscopy, Fourier transform infrared (FTIR) spectroscopy, and thermogravimetric analysis (TGA). The structural, thermal, and surface properties of synthesized membranes have been confirmed by FTIR spectroscopy, X-ray diffraction, TGA, and scanning electron microscopy. The proton exchange membranes have been characterized by their ionic conductivity and unit cell performance. The incorporation of IL-H<SUB>2</SUB>PO<SUB>4</SUB> and graphene oxide in the Nafion membrane increases its thermal stability. The ionic conductivity of the membranes increases with temperature and amount of IL-H<SUB>2</SUB>PO<SUB>4</SUB>. The highest ionic conductivity of 0.061 Scm<SUP>−1</SUP> has been achieved at 110 °C under anhydrous conditions which is 1.3 times higher than that of commercial Nafion 117. The synthesized membrane, Nafion/IL/GO, shows the best unit cell performance with a power density of 0.02 W cm<SUP>−2</SUP>, which is 13 times higher than that of the commercial Nafion 117 membrane at 110 °C.</P>