A study of polarization induced Lanthanum Strontium Cobalt Ferrite (LSCF) - Erbium Stabilized Bismuth (ESB) cathode / Gadolinium Doped Ceria (GDC) electrolyte interface of reversible solid oxide cells

Reversible Solid oxide cells (rSOCs) are electrochemical energy conversion devices to convert chemical energy of fuels such as hydrogen, natural gas to electricity with high efficiency and low greenhouse emission as compared to conventional power generation plants. RSOCs generally operate at high temperatures of 900-1000°C which leads to high system costs and performance degradation. Therefore, decreasing the operating temperature will provide more opportunities for the material selection and decreasing fuel cells’ cost to allow them competitive with traditional power generation system. However, reducing the operation temperature would result in an increase of ohmic resistance of electrode and electrolyte and electrode polarization losses at the electrode/electrolyte interface in the cell. One possible solution could be the utilization of new materials with higher electrical and ionic conductivity at lower temperature. Lanthanum Strontium Cobaltite Ferrite (LSCF) decorated with Erbium-Stabilized Bismuth (ESB) directly applied on Gadolinium-Doped Ceria (GDC) electrolyte cell was fabricated, tested and analyzed after 100 h of polarization with cathodic current of 1000 mAcm-2 at 750°C. Results show a larger segregation and migration of Erbium with a similar even if smaller behavior for Bismuth after polarisation. This mechanism leads to a reduction of impedance across the sample and consequently to lower losses in terms of power for reversible Solid Oxide Cell (rSOC) application. Results are compared with pristine LSCF to highlight the higher performance with the decoration.