Performance Characteristics of Solid Electrolytes under Steady-State Conditions

Parametric integral equations for the steady‐state terminal voltage and external current of a solid electrolyte energy conversion device are derived under the assumption that the anode and cathode chemical potentials remain invariant. Plots of terminal voltage, power delivered, and efficiency vs . external current are generated for yttria‐doped thoria at 1600°C by first inserting the appropriate functional dependencies for the ionic and electronic conductivities into the parametric equations and then systematically eliminating the common parameter. The formulas are also used to calculate and plot the chemical potential profiles inside the yttria‐doped thoria solid electrolyte under applied voltage (charging) as well as under load (discharging) conditions.