LONG-TERM THERMAL CYCLING OF PHLOGOPITE MICA-BASED COMPRESSIVE SEALS FOR SOLID OXIDE FUEL CELLS

摘要

Reliable sealants are one of the toughest challenges in advancing the solid oxide fuel cell technologies. One of the most stringent requirements for sealants is the thermal cycle stability. The sealants have to survive multiple thermal cycles during operation in stationary and transportation applications. Recently, researchers at the Pacific Northwest National Laboratory have developed a hybrid mica-based compressive seal with which leak rates were reduced to 2-4x10~(-2) to 10~(-3) sccm/cm at 800C. Long-term thermal cycling (up to 700 thermal cycles) will be conducted on the Phlogopite mica-based compressive seals. Open circuit voltage will be measured on a medium-sized (2"x2") 8YSZ plate with the mica seals during thermal cycling in a dual environment (2.75% H_2/Ar vs. air). The measured OCVs will be compared to the Nernst voltages to assess the sealing capability of the hybrid Phlogopite mica seals.