The role of TiO2 on the microstructure and the electrochemical behavior of Ce0.8Gd0.2O2-δ for solid oxide fuel cell electrolyte

Abstract Ce 0.8 Gd 0.2 O 2-δ (GDC) with various TiO 2 contents was prepared by a conventional mixed oxide method. The effects of doping the ceramic solid electrolyte (GDC) with titanium oxide were investigated with regard to crystal structure, microstructure, electrical property and fuel cell performance. The XRD analysis revealed the existence of a phase comprising a cubic fluorite structure. Above 2 mol% TiO 2 a second phase as Gd 2 Ti 2 O 7 was found. TiO 2 promoted grain growth of the ceria ceramics. The grain boundary (GB) conductivity of GDC-TiO 2 composite was increased by a small addition of TiO 2 . The maximum power density was achieved by the cell with GDC-1mol%TiO 2 as electrolyte.