Tailoring SPEEK/SPVdF-<i>co</i>-HFP/La<sub>2</sub>Zr<sub>2</sub>O<sub>7</sub> Ternary Composite Membrane for Cation Exchange Membrane Fuel Cells
Raja Pugalenthi Mariappan, Chaofeng Liu, Guozhong Cao, M. Ramesh Prabhu
Abstract
The sulfonated poly(ether ether ketone) (SPEEK) membrane has substantial property only with unification of acid-polymer and nanoparticles. The high stability of acid-based sulfonated poly(vinylidene fluoride-co-hexafluoropropylene) polymer is tailored with the SPEEK membrane to fine-tune the membrane stability, causing depletion in ionic conductivity. Various quantities of lanthanum zirconate (La2Zr2O7) (2, 4, 6, and 8 wt %) nanoparticles were impregnated into the blend membrane to elevate the ionic conductivity with enriched stability. The effects of more hydrophilic domains facilitate the proton hopping mechanism. The distinct properties of the prepared membrane are examined using X-ray diffraction (XRD), NMR, field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), thermogravimetric analysis (TGA), tensile tests, water uptake, etc. The homogeneous appearances of the membrane morphology are exposed. The thermal and mechanical stability of the nanocomposite membranes is validated by a tensile test, and obtained results are better than those of the pure SPEEK membrane. The maximum proton conductivity of the SPEEK/SPVdF-co-HFP/La2Zr2O7 (6 wt %) membrane is 1.53 × 10–2 S cm–1. The voltage–current measurement of the membrane is obtained in the single cell type at 80 °C under relative humidity (RH) 75% with the H2/O2 gas flow. The maximum current density and power density obtained are 78 mA cm–2 and 335 mW cm–2.