High performance of microtubular solid oxide fuel cells using Nd2NiO4+δ-based composite cathodes

Abstract

Nd₂NiO_4+δ infiltrated into porous yttria stabilized zirconia (YSZ) is proposed in this work as a cathode for solid oxide fuel cells (SOFCs). In order to obtain nickelate single phase, calcination times and temperatures of the salt precursors are studied. Anode supported microtubular cells using this cathode are fabricated and characterized, showing power densities of about 0.76 W cm⁻² at 800 °C and a voltage as high as 0.8 V. No degradation is detected after 24 hours under current load, assuring reasonable stability of the cell. Preliminary solid oxide electrolysis cell (SOEC) results show slightly better performances in comparison with SOFC operation. It is believed that infiltration of nickelate salt precursors followed by calcination proposed in this work avoids high temperature sintering of the nickelate phase with the electrolyte and as a consequence, prevents their reaction. For this reason, infiltrated nickelates are very attractive for their use as intermediate temperature (IT) SOFC cathodes.