Global Thermoelectric’s Integrated Cell Manufacturing of Planar SOFCs

Abstract

Global Thermoelectric Inc. has been actively engaged in integrated solid oxide fuel cell (SOFC) manufacturing technology research and development for the past five years. Global's current cell manufacturing process has three major operation units for fabrication of its anode supported planar cells. Anode substrates approximately 1 mm in thickness are produced by a single step tape casting process. The anode, electrolyte and cathode functional layers are screen-printed directly on the green anode substrate tape. The multi-layer green cells are sintered into complete cells through a continuous co-firing process. The tape casting, screen-printing and co-firing (TSC) processes evolved from the laboratory research stage to the pilot plant production stage over three years. Global is able to produce cells at a volume equivalent to 5 MW/year with greater than 90% yield. Global attributes this progress to the combination of advanced materials technologies, engineering principles and adherence to manufacturing discipline. Cells made by this integrated manufacturing process are capable of thermal and load cycling. Global's cell can produce over 1.4 W/cm 2 at 750°C. A long-term degradation rate approximately 1% per 1000 hours at a current density of 0.55 A/cm 2 was demonstrated over 6000 hours of testing. Global's cell performance can be attributed to the optimized microstructures developed by the integrated cell manufacturing process. In this paper, the process technology, microstructure and characteristics of Global's planar SOFCs will be presented in detail.