Nanostructured Ni/YSZ anodes: Fabrication and performance analysis

The design of state-of-the-art SOFC anodes limits the electrooxidation reaction inherently by its μ m-scaled microstructure. An increase in cell performance of anode-supported SOFCs (ASC) is achieved by a method, which induces the formation of an additional nanostructured Ni/YSZ layer in the electrochemically active region of the anode. This in-operando technique is based on a short-time application of a high current in reverse direction (reverse current treatment-RCT). In this contribution we investigate the nanostructured layer in a new model anode setup on a single crystalline YSZ substrate, guaranteeing homogenous experimental conditions due to simplified cell geometry. It is possible to control the RCT parameters and fabricate nanostructured layers (thickness 1100 nm) leading to an impressively low anode polarization resistance compared to technical SOFC anodes. TEM analysis provides new information of the serve interaction of YSZ with the adjacent Ni-phase during RCT, which is essential for controlling and optimizing the fabrication process.