2.4. Fuel cell operation
The single cell fixture was composed of an MEA and a pair of
graphite plates with a single serpentine flow channel of 0.8 mm
width and 0.7mmdepth for the anode, and a single serpentine flow
channel of 1.0 mm width and 1.0 mm depth for the cathode.
Hydrogen and air/oxygen were supplied in a counter-flow configuration.
For the wet condition, the cell temperature was kept at
80 C, while the inlet anode and cathode humidity was maintained
at 100% RH. For the dry condition, the cell temperature was kept at
80 C, whereas the inlet anode and cathode humidity was maintained
at 30%RH. For both conditions, the stoichiometric ratios of
hydrogen and air were 1.4 and 2.0, respectively. After a conditioning
operation of the cell at 0.7 A/cm2 for 15 h under the wet condition,
it was operated at 0.2 A/cm2 for 150 h, under both wet and dry
conditions.
membrane. The Pt loading was 0.4 mg/cm2 for the anode and
cathode decals. Membrane electrode assemblies (MEAs) were
assembled by hot-pressing (130 C, 1.5 MPa, 5 min) so that the
catalyst layers were in contact with the membrane. The MEAs,
which have an active electrode area of 25 cm2, were assembled into
a test cell. As a reference GDL, a GDL (X0086 IX51 CX173, hydrophobic
treated GDL with an MPL, Freudenberg-NOK) was used for
both the anode and cathode sides.
N2 atmosphere for 30 min.