Porous Ni/TiO2 substrates for planar solid oxide fuel cell applications

Anode substrates based on Ni/TiO2 cermets were fabricated for planar solid oxide fuel cells (SOFCs) with the aim of reducing the material costs and preventing thermoelastic bending of the currently used Ni/8YSZ-based cells. Ni/TiO2 substrates were produced via sintering of NiO/NiTiO3 powder compacts and subsequent reduction. The sintering behavior in air and the resulting microstructure were studied in detail. Excellent electrical conductivity and gas permeability was achieved before and after reduction due to coarse microstructure. The co-firing behavior of substrates coated with an anode layer and an 8YSZ electrolyte membrane was analyzed with the aim of identifying those sintering schedules which give flat cells with a gastight electrolyte. Thermoelastic bending of cells is negligible since the thermal expansion coefficient is well adjusted to the 8YSZ electrolyte. (C) 2001 Kluwer Academic Publishers.