Intermediate temperature SOFC single cell test using Nd1.95NiO4+δ as cathode

This work deals with SOFC single cell tests using neodymium nickelate Nd1.95MO4,6 as cathode material. This MIEC oxide exhibits high values of both surface exchange coefficient (k) and oxygen diffusion coefficient (D*), as well as high electronic conductivity, which result in an enhanced electrochemical activity with respect to classical materials. The SOFC cells were fabricated from an anode-supported electrolyte half-cell provided by InDEC B.V. Corporation, with a 36 mm diameter. The Nd1.95MO4+delta cathode was prepared as a two-stage electrode consisting of a thin interlayer of several hundred nanometers covered by a thicker layer of dozens microns. The Nd1.95MO4+delta oxide powders were synthesized using different routes in order to reduce the final annealing temperature, and to subsequently obtain submicronic powders. I-V characteristics of the single cells were investigated under hydrogen-air conditions. The power densities versus Current densities curves are reported and the results of impedance spectroscopy measurements performed under these operating conditions are discussed. (c) 2007 Elsevier Ltd. All rights reserved.