Preparation and Conductivity of Composite Apatite La_(9.33)Si_6O_(26)(LSO) - Zr_(0.85)Y_(0.15)O_(1.925) (YSZ)

摘要

A great challenge to reduce high operating temperature of solid oxide fuel cell (SOFC) to intermediate temperature SOFC (IT-SOFC, 500-750 °C), is the development of solid electrolyte materials with high ionic conductivity at intermediate temperature range. In response to this challenge, here we report a novel composite material La_(9.33)Si_6O_(26) (LSO)-Zr_(0.85)Y_(0.15)O_(1.925) (YSZ). LSO-YSZ composite synthesis was carried out by combining LSO with commercial YSZ (9:1, 8:2, 7:3) using hydrothermal method. In order to get dense pellet, all of the product were sintered at 1450 °C for 3 hours. X-ray diffraction pattern of the entire pellets show typical both of LSO and YSZ pattern which indicate that the composite was succesfully formed. The highest conductivity was detected in YSZ-7LSO (YSZ:LSO= 7: 3), i.e 1.72 x 10~(-4) Scm~-1 at 700 °C and also has low activation energy (0.88 eV). This result suggests that the LSO-YSZ composite materials are good oxide ion conductor and potential to be used as an alternative solid electrolyte in IT-SOFC technology.