A Highly-Performed, Dual-Layered Cathode Supported Solid Oxide Electrolysis Cell for Efficient CO2 Electrolysis Fabricated by Phase Inversion Co-Tape Casting Method

Abstract

Efficient conversion of CO2 to fuels through electrolysis is a promising approach for energy storage and CO2 utilization. In this study, Ni-YSZ cathode support with hierarchically oriented finger-like macro-pores is fabricated by phase inversion co-tape casting method to minimize the concentration polarization and enhance the cell performance. More important, an active cathode functional layer is introduced between support and electrolyte in order to decrease the activation polarization and further improve the cell performance. A bilayered YSZ/GDC electrolyte is also employed to achieve high ionic conductivity and low electronic conductivity, and thereby to improve the cell efficiency and lower the operation temperature. Consequently, the electrolyzer exhibits a relatively high electrolysis current density of −1.107 A cm−2 and a significantly low electrode polarization resistance of 0.32 Ωcm2 at 700°C and 1.3 V when the cathode and anode are exposed to 67%CO2-33%CO and ambient air, respectively, resulting from remarkably decreased concentration and activation polarization. Thermodynamics calculations imply that the cells may suffer from the carbon coke issue in the CO-rich atmospheres, but no evidence of coking has been observed by SEM and Raman Spectroscopy, indicating that further work should be done to deeper understand the coking issue during the CO2 electrolysis process.