Electrical Transport and Electric Power Generation Properties of Lanthanum Silicate Oxyapatite Ceramics Prepared by a Sol-gel Method

Abstract

Dense ceramics of lanthanum silicate oxyapatite with composition of La9.50(SiO4)6O2.25 were fabricated from a precursor prepared by a water-based sol-gel method and sintered at 1773 K; this temperature is considerably lower than the sintering temperature used in conventional solid-state reaction method. The electrical transport properties and solid oxide fuel cell(SOFC) performance of lanthanum silicate oxyapatite ceramics were investigated by measuring the total conductivity, electromotive force of an oxygen concentration cell, and SOFC performance test. The transference number of oxide ions was found to be unity between 773 K and 1273 K under oxygen partial pressures from 10-25 atm to 1 atm. An almost linear relationship was observed between the output current and the terminal voltage by the SOFC performance test.