ABSTRACT
Today, in every stage of life, we are in search of alternative sources of energy because the supply of conventional energies will someday be depleted. In this connection, the research on fuel cell technology is emerging due to its high efficiency and the fact that it is a green process [1, 2]. In this chapter, we concentrate on the planar solid oxide fuel cell (SOFC), which shows more potential than the other types of fuel cells, primarily due to its flexibility of fuels [3]. Actually, in practical application, several single SOFCs are stacked to make the final system. To get high efficiency or reduce the loss, the contact between interconnects and electrodes is subjected to high clamping pressures [4]. Therefore, it is of foremost importance to investigate the mechanical integrity in conditions before and after stack operation. In general, the planar design of the SOFC consists of a PEN (positive-electrolyte-negative) structure. Here, we have chosen the anode, electrolyte, and cathode layers as NiO-8YSZ, 8YSZ, and lanthanum strontium manganite (LSM), respectively [5]. Further, as the single cell is made of different brittle ceramic layers, the elastic mismatch stress may be enough to weaken the structural integrity of the cell. Moreover, thermally induced residual stresses due to the mismatch of thermal expansion between the anode, electrolyte, and cathode layers may take place during the sintering of single-cell assembly. In this connection, investigation of the mechanical properties of the various component layers of the single solid oxide fuel cell, especially at the scale of the local microstructural length scale, becomes an issue of paramount scientific and technological importance, as any mechanical disintegration of a multicomponent system actually initiates at its micro-/nanostructural length scale.
