Characteristics of NiO-YSZ anode based on NiO particles synthesized by the precipitation method

In order to increase the three phase boundary (TPB) length through lowering the NiO particles to submicro-size, NiO powder was synthesized by the precipitation method and the corresponding NiO-YSZ (8 mol% yttria-stabilized zirconia) composite anodes were investigated in this paper. The crystallite size of the as-synthesized NiO particle was 20–30 nm. The particles were agglomerated, but the agglomerates could be partially broken by grinding. The powder has an average particle size of 0.36 μm after grinding. NiO-YSZ anodes were fabricated by mixing the as-prepared NiO with commercial YSZ powders together. In order to form suitable porosity, flour was used as the pore-former, which played a key role in affecting the anode performance. Characteristics of the anodes, namely, shrinkage behavior, temperature-programmed reduction (TPR) measurement at a constant temperature (i.e., a modified TPR technique) and resistance characteristic during reduction were investigated. The maximum power density of the anode-supported YSZ film single cell was 905 mW/cm2 at 750 °C based on the Anode-30 (NiO, YSZ and flour was mixed in the weight ratio of 5:5:3). As a summary, high cell performance could be achieved at reduced temperature with the as-fabricated NiO-YSZ anode containing a suitable microstructure.