Composite Nafion-CaTiO3-δ membranes as electrolyte component for PEM fuel cells
Manufacturing new electrolytes with high ionic conductivity has been a crucial challenge
in the development and large-scale distribution of fuel cell devices. In this work, we present two
Nafion composite membranes containing a non-stoichiometric calcium titanate perovskite (CaTiO3-d)
as a filler. These membranes are proposed as a proton exchange electrolyte for Polymer Electrolyte
Membrane (PEM) fuel cell devices. More precisely, two different perovskite concentrations of 5 wt%
and 10 wt%, with respect to Nafion, are considered. The structural, morphological, and chemical
properties of the composite membranes are studied, revealing an inhomogeneous distribution of the
filler within the polymer matrix. Direct methanol fuel cell (DMFC) tests, at 110 °C and 2 M methanol
concentration, were also performed. It was observed that the membrane containing 5 wt% of the
additive allows the highest cell performance in comparison to the other samples, with a maximum
power density of about 70 mW cm-2 at 200 mA cm-2. Consequently, the ability of the perovskite
structure to support proton carriers is here confirmed, suggesting an interesting strategy to obtain
successful materials for electrochemical devices.