Page 28 - Introduction to Transfer Phenomena in PEM Fuel Cells

Introduction to Hydrogen Technology 17
– overall reaction:
+
2H (g) O (g) ⎯⎯→
2H O(liq)
2
2
2
Figure 1.7 shows the operating principle of an AFC. [1.6]

Figure 1.7. Operating principle of an AFC

Near atmospheric pressure, their operating temperature is limited to
80°C–90°C for a yield of 50%. However, this temperature can be higher
(250°C) in the case of operating under pressure and with a highly
concentrated electrolyte [BLU 07].
There are few applications for these batteries, the most significant ones
being those of NASA with the Apollo program. The AFC batteries are
still used in the shuttle (three by shuttles) to supply electricity at a power of
between 2 kW and 12 kW (the maximum power is 16 kW) and a voltage of
between 28 V and 32 V [WAG 03]. We can also mention Siemens
who developed some batteries, including a 20 kW in the 1970s and
1980s, for submarines. The power range of AFC batteries is between 1 kW
and 100 kW.