
297Charge and Water Transport in Fuel Cells
a large amount of hydrophilic regions through which proton can migrate.
Since proton conductivity depends on water content, it is essential that the
membrane is sufciently and uniformly hydrated from the anode side to the
cathode side to maintain effective transport of the proton.
The proton conductivity is then obtained from Equation 7.42 with |z
i
| = 1
for hydrogen ion (H
+
) as
σ
H
+
=
F
2
. (7.46)
A more detailed description of the construction and material composition
of polymer electrolyte membrane will be given in Chapter 9.
7.3.1.3 Ionic Conductivity in Ceramic Electrolyte Membrane
While a detai ...