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Chemistry · Glossary

What is Thermodynamic efficiency of a fuel cell?

Also known as: thermodynamic efficiency

Definition 9.14 University Chemistry — Year 2 · Chapter 9 — Thermodynamics of Electrochemical Cells

The thermodynamic efficiency of a fuel cell is the ratio of the electrical work it delivers to the heat its fuel would release by combustion at the same temperature, −ΔrH-\Delta_r H per mole.

Where the energy of one mole of hydrogen goes in a fuel cell at 298\, K (liquid water). Top: the heat a flame would release. Middle: the reversible cell, which must give up -T _r S = 48.7\, kJ as heat whatever its design. Bottom: a real cell working at 0.70\, V.
Where the energy of one mole of hydrogen goes in a fuel cell at 298 K298\,\mathrm{K} (liquid water). Top: the heat a flame would release. Middle: the reversible cell, which must give up −TΔrS∘=48.7 kJ-T\Delta_r S^\circ = 48.7\,\mathrm{kJ} as heat whatever its design. Bottom: a real cell working at 0.70 V0.70\,\mathrm{V}.
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