PDF/月刊誌論文/code:pg_1101_07 マテリアル インテグレーション 2011年1月号
MATERIALS INTEGRATION 21世紀,期待される新型電池と新しいイオン伝導性固体たち

燃料電池を指向したアパタイト型ランタンシリケート酸化物イオン伝導体
■著者
兵庫県立工業技術センター　環境・バイオ部 部長 吉岡 秀樹

■要約
Lanthanum silicate, La10Si6O27, with an apatite-type structure is a promising electrolyte material for solid oxide fuel cell (SOFC) applications. The oxide-ion conductivity of apatite-type lanthanum silicates is enhanced by introducing excess oxide ions and doping lower valent cations to the Si site. The highest conductivities of Mg doped lanthanum silicates with excess oxide ions are 70-80 mS cm-1 at 800℃ with very low activation energy of 0.4 eV. Structural analysis using high temperature neutron powder diffractions and MPF (MEM-based Pattern Fitting) shows that the excess oxide ions locate near the diffraction path promote oxide ion conduction perpendicular to the c axis. Power densities of the SOFCs using apatite-type lanthanum silicate ceramic as an electrolyte have increased rapidly. We have also developed anode support SOFC using lanthanum silicate films prepared by atmospheric plasma spraying.