Validation of Nd 2 NiO 4+ δ as Oxygen Electrode Material for Intermediate Temperature Solid Oxide Cells with LSGM Electrolyte

Abstract

The oxygen reduction reaction (ORR) was studied by Electrochemical Impedance Spectroscopy (EIS) for Nd 2 NiO 4+δ (NNO) electrodes deposited on La 0.9 Sr 0.1 Ga 0.8 Mg 0.2 O 2.85 (LSGM) electrolyte. The influence of NNO microstructure on the electrochemical performance was evaluated. The EIS measurements were carried out as a function of temperature (500 <1atm). Three contributions associated with the ORR were identified: at high (HF), medium (MF) and low frequencies (LF). The HF contribution was associated with oxygen ion transfer trough electrode/electrolyte interphase. The MF contribution was attributed to oxygen ions diffusion within the NNO. The LF contribution was related to O 2 -dissociative adsorption for NNO obtained by chemical routes, where the particle sizes are smaller. If NNO were obtained by Solid State Reaction, the LF element was associated with a convolution of dissociative adsorption and gas diffusion processes.