类钙钛矿复合氧化物La_(2-x)Sr_xNiO_4的合成及电学性能

Synthesis and electrical properties of La_(2-x)Sr_xNiO_4 perovskite-like oxides

采用柠檬酸硝酸盐燃烧法合成了La2-xSrxNiO4(LSN)阴极材料,并系统地研究了LSN的热膨胀性能、电子电导率,并考察了基于Ce1.8Sm0.2O1.9(SDC)电解质的LSN电极极化性能。结果表明,自燃烧产物经1000℃煅烧2h形成了单一的K2NiF4结构,25～800℃范围内,LSN材料的热膨胀系数在13.7×10-6～14.3×10-6K-1。La1.4Sr0.6NiO4电子电导率最高,为151.5～155.7S/cm(600～800℃)。极化测试结果显示,未掺杂的LSN具有最小的极化电阻(0.48Ω.cm2,800℃),电流密度为0.3A/cm2时,过电位约为0.083V。

Cathode materials La2-xSrxNiO4 （LSN） were synthesized using nitrate-citrate combustion route. In this paper, their thermal expansion behavior, electrical conductivity as well as cathodic polarization were systemically investigated based on SDC electrolyte. The results showed that the combustion products calcined at 1 000 ℃ for 2 hours formed single K2NiF4structural-phase. The average thermal expansion coefficients （TECs） of LSN specimens changed from 13.7 × 10^-6 - 14.3 × 10^-6 K^-1 at 25 - 800 ℃. La1.4-xSrxNiO4 had the largest electrical conductivity value with range from 151.5 to 155.7 S/cm at 600 -800 ℃. Polarization measurements showed that undoped LSN exhibited the lowest polarization resistance （0.48 Ω·cm^2,800 ℃）, the cathodic overpotential of which was about 0.083 V at the current density was 0.3 A/cm^2.