Designing the Solid Oxide Electrochemical Cell for Superior Thermal Shock Resistance

Abstract

Solid oxide fuel cells (SOFCs) have garnered significant interest as energy conversion systems. One of the primary challenges SOFCs face is the high vulnerability of ceramics to thermal stress, which results in slow startup/shutdown cycles. In this study, by controlling the intrinsic and extrinsic properties, we fabricated an SOFC capable of rapidly reaching operating temperatures exceeding 1173 K within a few seconds. 3YSZ (3 mol % yttria-stabilized zirconia), which has the highest mechanical fracture strength among available electrolyte materials, was used. By employing tape casting, the thickness was minimized to approximately 20 μm, resulting in an SOFC with excellent thermal shock resistance. The designed cell exhibits outstanding flexibility, providing a competitive advantage in mitigating thermal bending-induced stress. Experimental and theoretical analyses confirmed that the designed cell operated stably without crack formation, reaching its operational temperature within 3 s. Furthermore, this study verified the stability and durability of the startup/shutdown cycles, which were achieved within seconds for over 100 cycles. These outcomes represent a milestone in tackling the intrinsic thermal shock vulnerabilities of ceramics, contributing significantly to the development of SOFC technologies and, more generally, of better heat-resistant ceramics. © 2024 American Chemical Society.