The effect of ball milling parameters and Ni concentration on a YSZ-coated Ni composite for a high temperature electrolysis cathode

Ni/YSZ composite powders used as the cathode material for high temperature electrolysis were synthesized by the ball milling of Ni and YSZ powders. The effect of ball milling parameters and Ni concentration on microstructure of Ni/YSZ composite powders were investigated. The electrical conductivity of the composite was measured to examine its relationship with microstructure. Microstructural analysis of the ball-milled powder showed that YSZ particles were finely distributed over the surfaces of nickel particles and that the nickel particles appeared to be interconnected. This interconnection creates an electrically conductive pathway at room temperature. The conductive pathway was less developed at higher YSZ concentrations due to surface coverage of Ni surfaces by YSZ particles. Electrochemical properties of the composites were investigated high temperature electrolysis.