Environmental Engineering Reference
In-Depth Information
Fig. 4.2
Schematic view of fuel cells with proton conductor membrane
Fig. 4.3
Schematic illustra-
tion of electrochemical
reaction
In a similar way, fuel cell efficiency is highest at close to the equilibrium state.
When the current increases, the fuel cell moves away from its equilibrium state and
the voltage or efficiency is reduced (Fig.
4.4
). The degree of this reduction is de-
termined by the resistance of the fuel cell which is described by terms such as elec-
trolyte resistance, electrode reaction resistance, current collector resistance. An ef-
ficient fuel cell has small resistance, and the reduction in voltage is small even when
taking out a large current. In our analogy it can also be noted that when the luggage