Chapter 4 - Development of Fabrication/Integration Technology for Micro Tubular SOFCs

Abstract

A typical Solid oxide fuel cell (SOFC) consists of doped zirconia for an electrolyte, Ni cermet for an anode and doped lanthanum manganite for a cathode, and it has shown its long-term stability over 20,000 h operation as well as high power output up to 2 W/cm2 at 800°C. SOFCs have been recognized as a keystone of the future energy economy, and the development of SOFC systems has been an important issue in recent years. This chapter discusses development of micro tubular SOFCs, summarizes recent development of fabrication/integration technology for micro tubular SOFCs, and examines characteristics of micro tubular SOFCs. High-performance SOFCs lies in the design of the cell/bundle/stack and novel fabrication technology that can realize optimized electrode structures. By using recent development of fabrication/integration technology for micro tubular SOFCs with diameters of 0.8–2.0 mm in diameter operable at at/under 550°C are fabricated. Characterization of micro tubular SOFC is discussed in detail, including current collecting loss due to the dimension of the cell. For practical realization of the micro tubular SOFC system, further investigations of the tubular cells and the bundles are necessary to gain the knowledge necessary for understanding the following issues: stack design (manifold design); thermal distribution in the stack and thermal management (simulation); gas pressure loss in the stack/system and optimization of gas flow; fuel utilization; current collecting loss from the cathode matrix; and sealing technology.