Fabrication and characterization of Cu/YSZ cermet high-temperature electrolysis cathode material prepared by high-energy ball-milling method: I. 900 °C-sintered

Abstract

Cu/YSZ composites (40 and 60 vol.% Cu powder with balance YSZ) was successfully fabricated by high-energy ball-milling of Cu and YSZ powders at 400 rpm for 24 h, pressing into pellets (Ø 13 mm × 2 mm) and subsequent sintering process at 900 °C under flowing 5%-H 2/Ar gas for use as cermet cathode material of high-temperature electrolysis (HTE) of water vapor in a more economical way compared with conventional Ni/YSZ cermet cathode material. The Cu/YSZ composite powders thus synthesized and sintered were characterized using various analytical tools such as XRD, SEM, and laser diffraction and scattering method. Electrical conductivity of sintered Cu/YSZ cermet pellets thus fabricated was measured using 4-probe technique and compared with that of Ni/YSZ cermets. The effect of composites composition on the electrical conductivity was investigated and marked increase in electrical conductivity for copper contents greater than 40 vol.% in the composite was explained by percolation threshold.