The novel combination of electrostatic powder coating with suspension coating for fabricating the dense YSZ thin film on porous anode substrate

The novel combination of electrostatic powder coating with suspension coating is proved to be a feasible method for fabricating dense thin ceramic film on a porous ceramic substrate. In this paper, we research the particle packing and sintering characteristics of yttria stabilized zirconia (YSZ, 8 mol% Y2O3) powder layer fabricated by this method on NiO/YSZ porous substrates. The powder layer fabricated by electrostatic powder coating consists of agglomerations, which are loosely packed and form a net-like structure, which did not be sintered at 1450 °C. To improve the sintering characteristic of YSZ powder compact of this layer, an YSZ suspension is coated. The relative density of the green layer is about 52% after firing at 900 °C for 2 h and the pores are filled by the fine particles under capillary force, which is sintered to full all dense at 1450 °C for 5 h. The peak power density of the cells is 302 mW/cm2 at 800 °C. The open circuit voltage of the cell reaches 1.09 V at 800 °C. The conductivities of YSZ membrane and bulk at 700 °C are 0.0044 and 0.008 S cm−1. Results show that this is an effective method to fabricate dense thin films on the porous substrate.