Project Overview

In need of increasing energy security and ecological deliberation to our living environment, the efficient conversion of energy is in a special significant in our times. Connecting both, high efficiency and fuel flexibility, solid oxide fuel cells (SOFC, hereafter) are becoming important steep in to the direction of future of hydrogen society. The morphology of the anode microstructure is an important factor in determining the electrochemical performance of a cell and consequently of an entire stack of cells. A typical anode consists of a nickel phase (Ni), a yttria stabilized zirconia phase (YSZ, hereafter) and a pore phase. Each component plays a unique and important role in the transport processes inside an SOFC by providing a pathway for different species: the YSZ phase for oxygen ions, the Ni phase for electrons and the pore phase for gases (see Fig. 1). The electrochemical reaction can occur only in a place where all three phases meet each other, the so-called triple phases boundary (TPB, hereafter). It is generally accepted that the TPB plays an important role in determining the performance of SOFCs. Therefore, an anode is required to have as high a TPB density as possible to promote electrochemical reactions. TPB density decreases for various reasons during operation. It leads to a drop in performance. To maintaining a high TPB density during operation becomes a key issue into guaranteeing long and safe operation. Previous analysis and experiences show that these losses in performance mean that existing SOFC components are not yet qualified for long-term and reliable operation. To assure that a detailed knowledge about the degradation mechanisms of microstructure in a stack is needed.


Fig. 1 Schematic view on transport phenomena inside anĀ anode