Enhanced electrochemical activity and long-term stability of Ni–YSZ anode derived from NiO–YSZ interdispersed composite particles

Abstract

Nickel oxide–yttira stabilized zirconia (NiO–YSZ) interdispersed composite (IC) particles were prepared by mechanochemical processing using NiO and YSZ nanoparticles. Transmission electron microscopy (TEM) revealed that primary particles of YSZ (75 nm) and NiO (160 nm) were presented alternately in the composite particles. Specific surface area (SSA) decreased from 8.6 to 7.1 m 2 /g during the mechanochemical processing. The SSA reduction suggested that the chemically bound NiO/YSZ hetero-interfaces were formed during the processing. Scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDS) visualized that the anode made from the IC particles consisted of a three-dimensional textured structure of fine Ni and YSZ networks (grain size approximately 500 nm) with 34 vol% porosity. The anode demonstrated not only low polarization of 152 mV at 1 A/cm 2 even under operation at 700°C, but also long-term stability for 920 h.