Indexed on: 01 Jun '99Published on: 01 Jun '99Published in: Science China. Chemistry
The solid electrolytes, BaCe0.8Ln0.2O2.9(Ln: Gd, Sm, Eu), were prepared by the sol-gel method. XRD indicated that a pure orthorhombic phase was formed at 900°C. The synthesis temperature by the sol-gel method was about 600°C lower than the high temperature solid phase reaction method. The electrical conductivity and impedance spectra were measured and the conduction mechanism was studied. The grain-boundary resistance of the solid electrolyte could be reduced or eliminated by the sol-gel method. The conductivity of BaCe0.8Gd0.2O2.9 is 7.87 × 10-2 S· cm-1 at 800°C. The open-rireuit voltage of hydrogen-oxygen fuel cell using BaCe0.8Gd0.2O2.9 as electrolyte was near to 1 V and its maximum power density was 30 mW· cm-2.