| 초록 |
Nickel (Ni) -8 mol. % YSZ (Yttria Stabilized Zirconia) Cermet is a substance widely used as anode support for fuel electrode-supported solid oxide fuel cells. It should have high mechanical strength and long-term durability in the high-temperature, humidified hydrogen atmosphere of solid oxide fuel cells operating conditions. Ni-8YSZ cermet has excellent long-term durability, but its mechanical strength is low, and it is expensive. Therefore, many researchers are using Ni-3YSZ cermet, which has high mechanical strength and relatively low price. However, although Ni-3YSZ has high mechanical strength, long-term durability is significantly reduced. Ni particles are coarsened to reduce surface energy, and YSZ has been studied as a cause of reduced stability and reduced mechanical strength in the high-temperature, humidified hydrogen atmosphere. To overcome this, nano-silicon carbide (nano-SiC) was added to the Ni-3YSZ cermet, which was evaluated for mechanical strength and long-term stability with Ni-8YSZ and Ni-3YSZ. NiO-8YSZ, NiO-3YSZ, and NiO-3YSZ powder with nano-SiC added were mixed evenly through a ball mill process. The mixed slurry was dried in an oven, then ground, pelletized, and sintered. The sintered test piece was reduced at high temperature and in the high-temperature, humidified hydrogen atmosphere for 500 and 1000 hours, respectively. The mechanical strength was measured using the three-point flexural testing technique. The mechanical strength and long-term durability of the nano-SiC-added Ni-3YSZ specimens have been significantly improved, which prevents the coarsening of Ni particles through the nano-SiC addition and the secondary phase. The above results of improved stability on 3YSZ will be explained in this presentation.
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