Development of In-Situ Mechanical Testing Method for SOFC Components

Abstract

For the commercialization of solid oxide fuel cell (SOFC), in addition to the electrical reliability, it is also important to ensure the mechanical reliability of SOFC. Thus, the establishment of a suitable mechanical testing method under various temperatures and oxygen partial pressure conditions is a prerequisite for the development of reliable SOFCs. This paper presents the experimental results of the investigation of elastic modulus and fracture strength on the SOFC components under reducing conditions. An in-situ mechanical testing method was developed in order to investigate the elastic modulus and fracture strength of solid oxide fuel cells components under high oxidizing/reducing environments. The elastic modulus was shown to change under reducing condition, and the behavior was most likely due to non-stoichiometry. It was demonstrated that the in-situ mechanical testing method enabled us to estimate the internal stress in the SOFC cell and stack.

Chemomechanics of ionically conductive ceramics for electrical energy conversion and storage

“…However, thermal stresses that may result from the rapid quenching process could distort mechanical testing results. Indeed, Watanabe et al found that the fracture stresses of quenched samples of GDC annealed at low P O2 were low relative to those measured in situ, and attributed this difference to the effect of quenching the samples [84].…”

“…This approach also provides measurement of the internal friction of these materials. Researchers from that Tohoku University-based team have also developed a device that can estimate the fracture stress and elastic modulus in similar high temperature, controlled atmosphere environments using a small punch [83,84]. Alternatively, instrumented nanoindentation is under development for environmentally controlled, in situ analysis of elastoplastic and fracture properties.…”