Characterization of (Ni–Cu)/YSZ cermet composites fabricated using high-energy ball-milling: effect of Cu concentration on the composite performance

Abstract

Bimetallic composite materials, also known as (Ni–Cu)/YSZ cermets, were successfully fabricated using high-energy ball-milling for possible use as cathode materials in high-temperature electrolysis cells. The fabricated (Ni–Cu)/YSZ cermet was characterized using XRD, SEM and laser diffraction and scattering analyses. XRD analysis demonstrated that the (Ni–Cu)/YSZ cermet powders were bimetallic Ni–Cu composites with YSZ particles randomly dispersed over the metal surface. Increasing the Ni/Cu ratio resulted in a decrease in the (Ni–Cu)/YSZ particle size and an increase in electrical conductivity. The increase in conductivity is attributed to the improved connectivity between the (Ni–Cu)/YSZ particles caused by the decrease in particle size. For this reason, 50% Ni–10% Cu/YSZ cermet was chosen to be the HTE cathode in a self-supporting planar unit cell, and its electrochemical performance was examined. Furthermore, the effects of high-energy ball-milling parameters on the morphology and electrochemical performance of (Ni–Cu)/YSZ cermets were characterized.