Ionic Conductivity of Bi2NixV1-xO5.5-3x/2 (0.1 ≤ x ≤ 0.2) Oxides Prepared by a Low Temperature Sol-Gel Route

摘要

Solid oxides fuel cells (SOFCs) is one technology that could contribute toward future sustainable energy. One of the most important components of an SOFC is the electrolyte, which must have high ionic conductivity. Cation substitution of vanadium in Bi_4V_2O_(11) yields a family of fast oxide ion conducting solids known collectively as the BIMEVOXes (bismuth metal vanadium oxide), which have the potential to be applied as electrolytes in SOFCs. The purpose of this work is to study the effect of Ni concentration, when used as a dopant, on the ionic conductivity of Bi_2Ni_xV_(1-x)O_(5.5-3x/2) (BINIVOX) oxides (0.1 ≤ x ≤ 0.2) when prepared by a sol gel method. The gels were calcined at 600 °C for 24 h to produce pure BINIVOX. These oxides were found to exhibit the γ-phase structure with tetragonal symmetry in space group I4/mmm. Ionic conductivity of BINIVOX at 300 °C were 6.9 × 10~(-3) S cm~(-1), 1.2 × 10~(-3) S cm~(-1), and 8.2 × 10~(-4) S cm~(-1), for x = 0.1; 0.15; and 0.2; respectively; and at 600 °C were 1.1 × 10~(-1) S cm~(-1), 5.3 × 10-2 S cm~(-1), and 2.8 ×10~(-2) S cm~(-1), for x = 0.1; 0.15; and 0.2; respectively.