Page 58 - Introduction to Transfer Phenomena in PEM Fuel Cells

1.3.3. Operation and aging problem
Table 1.10 summarizes the characteristics and performance of the
PEMFC [BOU 07]. Introduction to Hydrogen Technology 47
Characteristics and performance
Operating temperature 60 to 80°C
Operating pressure 1 to 3 bars
Electrical efficiency 40 to 50%
Actual voltage 0.6 to 0.95 V
Current density Up to A/cm²
1,000 to 2,000 hours (value in 2005)
Up to 4,000 hours [HFC Consulting Group]
Lifetime
Current tests reach 8,000 hours (with a very quick start-
up time)
Table 1.10. The performances of a PEM fuel cell

These fuel cells have some advantages [BLU 07, BOU 07]:
– very fast start-up time;
– very fast response time;

– compactness;
– insensitive to CO 2;
– the electrolyte is solid. There is therefore no risk of electrolyte leakage;

– the operating temperature is low;
– the mass power is high, the power density can reach 1 kW/kg.

However, they have some disadvantages:

– high membrane cost;
– the membranes must be maintained permanently in a good state of
hydration to promote the transport of protons. Otherwise, there is a risk of
damage to the membrane;

– they are sensitive to carbon monoxide, which poisons catalytic sites.