Investigation of Nafion®/HPA composite membranes for high temperature/low relative humidity PEMFC operation

Solid-state electrochemical behavior of Keggin-type borotungstic acid single crystal

“…The materials used for solid-state voltammetry should contain not only reactive redox species, through which fast reversible electron transfer is possible, but also fairly large amounts of mobile counter cations to keep the electroneutrality. Such materials can have potential application as charge storage in batteries and supercapacitors [3], electrochromic devices [4], corrosion protection [5,6], medicine [7], and fuel cell research [7][8][9][10][11][12][13][14][15]. The important physicochemical parameters, such as porosity, degree and type of solvation, effective diffusion coefficient of charge propagation, concentration of redox species, should be taken into account during evaluation and selection of solid electrolytes.…”

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

“…Nafion TM /Mordenite operating on hydrogen/oxygen at ambient pressure achieve 0.6 V at 280 mA/cm 2 for an operating temperature of 110 • C but the performance quickly decays with increasing temperature [33,34]. Nafion TM /PTA (phosphotungstic acid) operating on hydrogen/oxygen at ambient pressure achieve 0.6 V at 180 mA/cm 2 for an operating temperature of 120 • C [35], and Nafion TM -Teflon Zr(HPO 4 ) operating on hydrogen/oxygen at 120 • C achieved 0.6 V at 400 mA/cm 2 [32]. While performance is significantly lower than PEM Nafion TM performance when operated at 80 • C and ambient pressure with saturated reactants, it is roughly equivalent to the performance of Nafion TM /phosphoric acid [36], however there are little to no data on the durability of these membranes at fuel-cell operating conditions Durability of the membrane has been studied by numerous researchers [37][38][39][40][41].…”

Organic/Inorganic Nanocomposite Membranes Development for Low Temperature Fuel Cell Applications

“…Perfluorosulfonic acid based organic/ inorganic composite membranes with different heteropolyacid (HPA) additives have been investigated as alternate materials for low humidity PEMFC operation (Giordano et al, 1996;Ramani et al, 2004Ramani et al, , 2005aRamani et al, ,2005bTazi & Savadogo, 2000. Two major factors limiting the performance of Nafion ® /HPA composite membranes are (Ramani et al, 2005b): (i) the high solubility of the HPA additive and (ii) the large particle size of the inorganic additive within the membrane matrix (Ramani et al, 2004(Ramani et al, , 2005a.…”

“…Two major factors limiting the performance of Nafion ® /HPA composite membranes are (Ramani et al, 2005b): (i) the high solubility of the HPA additive and (ii) the large particle size of the inorganic additive within the membrane matrix (Ramani et al, 2004(Ramani et al, , 2005a. Stabilization technique have been developed (Ramani et al, 2005a) to limit the solubility of the HPA additive.…”