Abstract

Synthesis and characterization of sulphonated poly (ether ether ketone)-phosphorized (zirconia) nano-composites as polymer electrolyte for fuel cell application

Author(s): Vijayalakshmy Naagaraj, R.Parthiban, Guhan Srinivasan*

Polymer blends of Sulphonated Poly Ether Ether Ketone (SPEEK)/Phosphorized Zirconia (PZD) with varying concentrations of PZD, were considered asmaterials for synthesizing PolymerElectrolyteMembranes (PEM). The PZD was added to check for variations in the mechanical stability, solvent absorption and proton conductivity of the composites with virgin SPEEK. The membranes were cast from solution using N,Methyl-2- Pyrrolidone (NMP) as solvent. Preliminary lab results showed a decrease in Ion Exchange Capacity (IEC) for composites fromvirgin SPEEK, a decrease in the water and methanol absorption was evident in the composites. FTIR confirmed the presence of sulphonic acid groups in the membranes and XRay Diffraction (XRD) confirmed the amorphous nature of the composites. Scanning Electron Microscopy (SEM) showed good homogeneity of the composites without any phase separations. Thermal analysis confirmed thermal stability of the composites membranes upto 250°C and tensile test measurements showed higher tensile strength for the composites than virgin SPEEK. Electrochemical Impedance (EIS) showed an increase in proton conductivity for the composites when compared to virgin SPEEK. After characterization, Membrane Electrode Assembly (MEA) was fabricated with Nafion, SPEEK, SPEEK-PZD for performance evaluation of the membranes. The composites showed higher current density when compared to virgin SPEEK and Nafion.