Fluoride-based electrolytes and their applications for intermediate temperature ceramic fuel cells

This chapter focuses on fluoride-based electrolytes and their applications for intermediate temperature ceramic fuel cells. Among all fuel cell (FC) technologies, the solid oxide fuel cell (SOFC) can utilize a number of different fuels. The conventional SOFCs use a ceramic electrolyte, e.g., yttria-stabilized zirconia (YSZ), and operate at high temperature, typically 1000°C. The high operating temperature puts very high demands on the materials and technology, which poses a major challenge for the further development of SOFCs into the market. For developing cost-effective SOFCs, much effort has been devoted to obtain a lower operating temperature. All these efforts have, however, limitations due to the deficiency of technology and the stability of the material. Ceramic fuel cells (CFCs) are sometimes used as a more general term for fuel cells based on ceramic materials, which have the desired properties. In the chapter, the focus is on possible proton and oxygen ion conduction in fluoride-based electrolytes that may be of interest for fundamental and applied research. Also, the focus is to develop new advanced CFCs for intermediate temperatures.