Molten Carbonate Fuel Cell performance analysis varying cathode operating conditions for carbon capture applications

The results of a systematic experimental campaign to verify the impact of real operating conditions on the performance of a complete Molten Carbonate Fuel Cell (MCFC) are presented. In particular, the effects of ageing and of different contents of water, oxygen and carbon dioxide in the cathodic feeding stream are studied through the analysis of current-voltage curves and Electrochemical Impedance Spectroscopy (EIS). Based on a proposed equivalent electrical circuit model and a fitting procedure, a correlation is found among specific operating parameters and single EIS coefficients. The obtained results suggest a new performance monitoring approach to be applied to MCFC for diagnostic purpose. Particular attention is devoted to operating conditions characteristic of MCFC application as CO2 concentrators, which, by feeding the cathode with exhaust gases, is a promising route for efficient and cheap carbon capture.