Revealing Hexadecyltrimethylammonium Chloride (HDTA) Intercalated Bentonite in Sulfonated Poly(ether ether ketone) as Nanocomposite Membrane Electrolyte for Direct Methanol Fuel Cells

Abstract

Hexadecyltrimethylammonium chloride (HDTA) intercalated Bentonite (HDTA-B) was dispersed in sulfonated polyether ether ketone (sPEEK) to form nanocomposite membrane electrolytes for direct methanol fuel cells (DMFC). HDTA intercalation to Bentonite is confirmed through various characterization techniques. The physico-chemical properties for the formed nanocomposite membranes of sPEEK/HDTA-B with various ratio were studied by determining its ion exchange capacity (IEC), water/methanol sorption and proton conductivity in conjunction with mechanical and thermal stability. Methanol cross-over for the composite membranes is restricted in comparison to pristine sPEEK confirmed via linear sweep voltammetry (LSV) by determining methanol oxidation current. Cell polarization reveals that, the optimized sPEEK/HDTA-B (80:20 wt ratio) composite membrane exhibit higher peak power density of 153 mW/cm2 while pristine sPEEK membrane show peak power density of 73 mW/cm2 only. These properties confirm that sPEEK/HDTA-B composite membranes is an viable option as electrolyte in DMFC.