固相反应对钆掺杂二氧化铈和钇掺杂铈酸钡电解质电化学性能的影响

Effects of Solid-State Reaction on Electrical Chemical Properties of Gd-doped CeO_2 Electrolyte and Y-doped BaCeO_3 Electrolyte

采用溶胶–凝胶燃烧法和机械混合法制备CeO2-BaCeO3、Ce0.8Gd0.2O1.9(GDC)-BaCeO3、CeO2-BaCe0.8Y0.2O3-δ(BCY)及GDC-BCY复合粉末,复合粉末中两相的摩尔比为1∶1,并在1550℃保温烧结5h。研究掺杂元素对掺杂CeO2与掺杂BaCeO3固相反应的影响,并研究了固相反应后GDC-BCY复合电解质的电化学性能。结果表明:掺杂元素能够抑制BaO的挥发,促使GDC-BCY复合电解质发生固相反应,形成以BaCe1-x-yGdxYyO3-α相为主的显微组织,其电导率大于单相BCY,略小于单相GDC。GDC-BCY电解质的单电池在700℃时的最大功率密度为0.657W/cm2,均高于相同条件下BCY、GDC电解质的单电池性能。

CeO2-BaCeO3, Ce0.8Gd0.2O1.9 (GDC)-BaCeO3, CeO2-BaCe0.8Y0.2O3–δ(BCY) and GDC-BCY composite powders (in a molar ratio 1:1) were prepared via a sol-gel combustion method and a mechanically-mixing method. The effect of doping elements on the solid-state reaction between doped CeO2 and doped BaCeO3 at a sintering temperature of 1 550℃ was investigated. The electrochemical properties of GDC-BCY composite electrolyte were investigated. The results show that the doping of elements into CeO2-BaCeO3 suppresses the evaporation of BaO, and promotes the solid-state reaction between GDC and BCY. The GDC-BCY composite electrolyte sintered at 1 550℃ produces a perovskite phase of BaCe1–x–yGdxYyO3–α. The conductivity of the GDC-BCY pellet after solid-state reaction is much greater than that of the single phase BCY, and slightly smaller than that of the single phase GDC. The single cell with GDC-BCY composite electrolyte has a peak power density of 0.657 W/cm2 at 700℃, which is greater than that of the cells with the GDC or BCY electrolyte.