Nafion composite membranes containing either hydrated tin oxide (SnO 2·nH2O) or sulphated tin oxide (S-SnO2) at 5 and 10 wt.-% were prepared and characterised. The structural and electrochemical features of the samples were investigated using X-ray diffraction, electrochemical impedance spectroscopy, methanol crossover and direct methanol fuel cell (DMFC) tests. Highest conductivity values were obtained by using S-SnO2 as filler (0.094 S cm-1 at T = 110°C and RH = 100%). The presence of the inorganic compound resulted in lower methanol crossover and improved DMFC performance with respect to a reference unfilled membrane. To improve the interface of the membrane electrode assembly (MEA), a layer of the composite electrolyte (i.e. the Nafion membrane containing 5 wt.-% S-SnO2) was brushed on the electrodes, obtaining a DMFC operating at 110°C with a power density (PD) of 100 mW cm-2 which corresponds to a PD improvement of 52% with respect to the unfilled Nafion membrane.
- Direct Methanol Fuel Cells
- Methanol Crossover
- Performance Improvement
- Proton Exchange Membrane
ASJC Scopus subject areas
- Renewable Energy, Sustainability and the Environment
- Energy Engineering and Power Technology