Electrochemical performance of CO2 electrolysis in an electrolyte-supported (NiO-YSZ/NiO-SDC/ScSZ/LSCF-GDC/LSCF) solid oxide electrolysis cell

Abstract This study investigated the electrochemical performance of CO2 electrolysis in an electrolyte-supported (NiO-YSZ/NiO-SDC/ScSZ/LSCF-GDC/LSCF) SOEC button cell at different temperatures (700, 750, 800, and 850 °C), CO2 gas concentrations (10, 30, and 60%), and applied voltage under OCV and electrolysis conditions. From FE-SEM analysis of the pristine cell, porous fuel and air electrode layers adhere well with the dense electrolyte. A smooth transition from SOFC to SOEC mode occurs across the OCV, signifying the reversibility of the cell. Higher temperatures favor fast electrochemical reaction kinetics. Area-specific resistance (ASR) values are lower in the SOFC than in the SOEC. The ASR value decreases as the CO2 concentration decreases from 60 to 10%. High potential helps electrode activation and enhances the activity. At 1.5 V, the Rp values for 10 and 30%CO2 gas concentration are 8.09 Ω.cm2 and 34.71 Ω.cm2, respectively. The CO2 gas concentration significantly affects the Rp value. The gas diffusion resistance predominantly contributes to the total polarization resistance. Graphical Abstract