A cell requiring voltage in excess of the theorotical potential is said to be
Answers
Explanation:
4.1.1 Electrochemistry
Cell voltage is modelled as the sum of the reversible and significant irreversible voltages [2], assuming identical cells, stack voltage is cell voltage multiplied by the number of cells.
Reversible fuel cell voltage is calculated using the Gibbs free energy of hydrogen reaction with a liquid water product; changes in product and reactant composition are accounted for using the Nernst equation. Cathode activation overvoltage and fuel crossover are both modelled using the Tafel equation. Mass transport voltage loss is modelled empirically as an exponential function of current and ohmic voltage loss is calculated using Ohm's law. The stack voltage/current relationship has been validated using experimental data of a 30 kW EC fuel cell system published in [6].