Loss Mechanisms in Fuel Cells

摘要

The fuel cell, which is a highly promising candidate for high efficiency energy conversion, is not reaching expected conversion efficiencies of v > 0.5 yet. Parallel to standard explanations of loss mechanisms by means of overvoltages, a thermodynamic of addressing irreversibilities by calculating local entropy production rates may be helpful. Entropy production rates are calculated by multiplying local transport fluxes with appropriate driving forces, i.e., gradients of temperature, chemical potentials and electric potentials. These gradients have to be calculated by solving the set of constitutive balance equations. Before this tedious task is done, simplified model equations have to be used. The reversible fuel cell is the starting point of analysis.