Electrochemical behaviour of La0.8Sr0.2MnO3--infiltrated Ba0.5Sr0.5Co0.8Fe0.2O3- under anodic overpotential

Solid oxide fuel cells (SOFCs) and electrolysers (SOECs) are currently considered as promising devices to be used in distribution and storage electrical net where renewables operate, because of their high efficiency and flexibility in terms of energy fluctuations. Our research group has recently studied the La0.8Sr0.2MnO3-δ-infiltrated Ba0.5Sr0.5Co0.8Fe0.2O3-δ system on Sm0.2Ce0.8O2- supporting electrolyte (LSM-BSCF/SDC), as electrode for SOFCs, under cathodic overpotentials. It was demonstrated a positive effect of LSM both on performance (polarisation resistance) and long-term stability. However, both pristine BSCF and infiltrated LSM-BSCF electrodes showed unexpected increasing of polarization resistance with increasing cathodic overpotential, namely when a net cathodic current flowed through them [1]. In view of these results, a similar BSCF and LSM-BSCF system on SDC-supporting electrolyte was studied under anodic electrochemical conditions, to explore the behaviour of this electrode as anode in SOEC mode. Due to gas evolution from reaction sites, electrolysis systems usually exhibit huge delamination [2], so the electrode porosity was accurately optimised using a graphite-based pore former. The results of this investigation will be presented.