Improvement of Mechanical Strength and Long-Term Durability on Anode Support for Solid Oxide Fuel Cells by Adding Nanomaterials

Abstract

This study improves the mechanical strength and long-term durability of Ni-8YSZ, a commonly used anode support(AS) for Solid Oxide Fuel Cells (SOFC). Instead of Ni-8YSZ, Ni-3YSZ is due to its high mechanical strength and low cost. 3YSZ alone had the disadvantage of degradation of mechanical strength in high-temperature, humidified hydrogen atmospheres due to phase transformation. The addition of nano-ZrO2 and nano-WO3 was expected to improve mechanical strength and long-term durability due to the Hall-Petch equation. For uniform dispersion, NiO and 3YSZ powders were ball-milled for 100 hours, and nano-ZrO2 or nano-WO3 was also added. The powders were sintered at 1400 oC for 5 hours. Sintered specimens were reduced at 750 oC in a hydrogen atmosphere for 8 hours. The reduced specimens were reduced for 500 and 1000 hours, respectively, at 900 oC in a humidified hydrogen atmosphere, which is an accelerated atmosphere. Ni-3YSZ with nano-ZrO2 added had greatly improved mechanical strength and long-term durability.