Co/Ni掺杂SrTi_(0.3)Fe_(0.7)O_(3–δ)钙钛矿电极材料制备及性能

Fabrication and Characterization of Co/Ni Substituted SrTi_(0.3)Fe_(0.7)O_(3–δ) Perovskite Electrode

以Sr Ti_(0.3)Fe_(0.7)O_(3–δ)(STF)为基础,研究了B位Co、Ni掺杂Sr Ti_(0.3)(Fe_(1–x)Co_x)_(0.7)O_(3–δ)(STFC)和Sr Ti_(0.3)(Fe_(1–y)Ni_y)_(0.7)O_(3–δ)(STFN)钙钛矿氧化物的成相过程及其在还原气氛中的结构演变规律,并进一步表征了其用于固体氧化物燃料电池(SOFC)对称电极的电化学性能。结果表明:Co和Fe可以在B位无限互溶,形成Sr Ti_(0.3)Fe_(0.7)O_(3–δ)–Sr Ti_(0.3)Co_(0.7)O_(3–δ)固溶体系;但当Ni替换Fe的比例超过约30%时就会出现明显的Sr_2Fe_2O_5杂相。在还原气氛中,STFC和STFN的结构稳定性随Co或Ni掺杂量的增加而降低,并逐渐由ABO_3结构转变为富AO相的钙钛矿衍生结构,同时伴随着Co基或Ni基金属相的生成。在850℃和加湿氢气燃料下,La_(0.8)Sr_(0.2)Ga_(0.83)Mg_(0.17)O_(3–δ)电解质支撑SrTi_(0.3)(Fe_(0.9)Ni_(0.1))_(0.7)O_(3–δ)和Sr Ti_(0.3)(Fe_(0.9)Co_(0.1))_(0.7)O_(3–δ)对称电池的最大功率密度分别达到约1.00和0.87 W/cm^2,表现出较好的电化学性能和实用前景。

Cobalt and nickel substituted SrTi0.3Fe0.7O3–δperovskite oxides,i.e.,Sr Ti0.3(Fe1–xCox)0.7O3–δ(STFC)and Sr Ti0.3(Fe1–yNiy)0.7O3–δ(STFN),were synthesized.Their structure evolutions in reducing atmospheres were investigated,and their electrochemical properties as symmetrical electrodes in solid oxide fuel cell were characterized.The results show that solid solutions from Sr Ti0.3Fe0.7O3–δto Sr Ti0.3Co0.7O3–δare effectively synthesized,and impurity phases of Sr2Fe2O5 occur in STFN system with a substituted nickel ratio of>30%to iron.After reduction in reducing atmosphere,the structure stability of STFC and STFN decreases with the increase of doping amount of Co or Ni,and the ABO3 structurechanges to AO-rich perovskite-derived structure and cobalt-or nickel-based metallic phases appear.Sr Ti0.3(Fe0.9Ni0.1)0.7O3–δand SrTi0.3(Fe0.9Co0.1)0.7O3–δsymmetrical cells with La0.8Sr0.2Ga0.83Mg0.17O3–δelectrolyte supports both have the maximum power densities of 1.00 and 0.87W/cm2,respectively,in wet hydrogen fuel,which could be used for the promising applications.