Addressing degradation of Ni/YSZ cermet fuel electrode in reversible solid oxide cells

Ni cermet fuel electrodes yield excellent electrochemical performance in solid oxide cells (SOCs), but their long-term stability is hindered by degradation mechanisms related to Ni agglomeration. While microstructure engineering can slow this degradation, it remains an intrinsic issue. Here, a new approach is presented to mitigate this degradation through infiltration of cerium oxides. This study shows that adding nanostructured CGO reduces degradation and enhances stability in the reversible mode. Although some agglomerations is observed, it does not impact cell performance. CGO-infiltrated cells exhibited no signs of degradation over 650-hours in reversible mode at 750°C, alternating between high hydrogen concentration (97% H₂ and 3% H₂O) at 0.8 V and high steam concentration (10% H₂ and 90% H₂O) at 1.27 V. Generated current increased in FC mode (from 0.20 to 0.31 Acm⁻²) and from 0.39 to 0.65 Acm⁻² in EC mode. In contrast, non-infiltrated cells showed a decline in EC mode from 0.67 to 0.2 A cm⁻² and in FC mode from 0.49 to 0.31 Acm⁻² after 400h. This offers a promising route to improving SOCs. Ni agglomeration's minor effect on electrochemical activity suggests the reaction has moved from the triple-phase boundary at the electrode gas interface to the double-phase boundary.