Numerical and experimental investigation of a cathode-supported microtubular solid oxide electrolysis cell from current and temperature variations in-situ assessed with electrode-segmentation method

Abstract

The electrode segmentation method has been applied to experimentally assess the current and temperature distributions in a cathode-supported microtubular solid oxide electrolysis cell (mt-SOEC). A detailed three-dimensional SOEC model considering the mass/momentum/charge/energy transfer is also developed to explain the in-situ working mechanism with spatial current and temperature variations considering the electrochemical performance and degradation. Both the experimental and numerical results reveal that the electrode-segmentation method exhibits notable nonuniform current and temperature distributions among the segments (up-, mid-, and downstream). Reactant starvation in the mid- and downstream regions leads to spatial current and temperature variations, with the largest temperature gradient observed and predicted between the up- and midstream regions. Further analysis of the temperature variations indicates that endothermic electrochemical Peltier heat in the air (oxygen) electrode (anode) is the primary cause of temperature decrease from 1.0 V to 1.3 V, while heat production with the overpotentials in the fuel (hydrogen) electrode (cathode) dominates temperature increase above 1.3 V.