Electrical and mechanical properties of 25 wt% tetragonal/cubic zirconia based composite thin films prepared by combination of aqueous tape casting and net shape methods

Abstract

Yttria doped zirconia based are the most important solid electrolytes for high temperature solid oxide fuel cell application. In this study, the tetragonal/cubic zirconia composite thin films are prepared by combination of aqueous tape casting and net shape method. The phases and microstructure of the samples are studied by X-ray diffraction and scanning electron microscope respectively. The microhardenss and toughness of thin films are measured by Vickers microhardness test. The nanohardness and Young's modulus of the specimens are evaluated by nanoindentation method. The electrical conductivity is determined by electrochemical impedance spectroscopy method. It is found that the composite electrolyte with 25 wt% of tetragonal phase content has improved mechanical and electrical properties at low temperatures and can be a suitable electrolyte for intermediate temperature solid oxide fuel cells.

Synthesis and Characterization of Gadolinium-Doped Zirconia as a Potential Electrolyte for Solid Oxide Fuel Cells

“…Doping zirconia with various cations such as Ca 2+ , Mg 2+ , Sc 3+ , Y 3+ , and some other rare earth metal cations such as Yb 3+ , Gd 3+ , Nd 3+ , and Sm 3+ result in the formation of stabilized zirconia with fcc cubic structure that offers excellent ionic conductivity, particularly above 1000 • C [15]. Introducing certain amounts of the tetragonal gadolinia (Gd 2 O 3 ) into the zirconia structure can create a stable gadolinium zirconate with various cubic, tetragonal, and monoclinic phases offering high ionic conductivity and thermal stability [16,17]. Gadolinium-doped zirconia (GDZ: Gd 2x Zr 2(1−x) O 4-x ) can also be used as a promising alternative top coating material to improve the conductivity and thermochemical stability of YSZ [18,19].…”