SPEEK/PES composite membranes as an alternative for proton exchange membrane in microbial fuel cell (MFC)

A solid polymer electrolyte (SPE) membranes were synthesized by incorporation of sulfonated poly(ether ether ketone) (SPEEK) in poly(ether sulfone) (PES) for electricity generation in microbial fuel cells (MFC). The composite membranes were prepared at 5% percent weight of SPEEK mixed with PES by phase inversion method and characterized by measuring proton conductivity, oxygen diffusion, water crossover and level of biofouling. Membrane electrode assemblies (MEA) were made by hot pressing the composite membranes with a Pt-loaded cathode on one side of membranes. The MEA, with effective area of 9 cm², were tested using single chamber MFC. The blended SPEEK/PES membrane had low resistivity to water crossover and oxygen diffusion while high in conductivity compared to Nafion and PES membranes. The MFC using the composite membranes generated an average power density of 140 mW m^-2 which was double that produced by MFC using Nafion membranes in every fed-batch cycle which lasted for 24 hours. The experimental results suggested that SPEEK/PES composite membrane could be a promising alternative to costly perfluorosulfonate membranes as proton exchange membrane in MFC system.