A位缺陷对(Pr_(0.5)Sr_(0.5))_(1-x)Fe_(0.9)Ru_(0.1)O_(3-δ)(0≤x≤0.2)阳极材料电化学性能及稳定性影响的研究

Effects of A-site deficiency on electrochemical performance and stability of (Pr_(0.5)Sr_(0.5))_(1-x)Fe_(0.9)Ru_(0.1)O_(3-δ)(0≤x≤0.2)anode material

通过燃烧法制备了不同A缺位的(Pr_(0.5)Sr_(0.5))_(1-x)Fe_(0.9)Ru_(0.1)O_(3-δ)(PSFR x,x=0,0.1,0.2)钙钛矿氧化物,并将其用作固体氧化燃料电池(Solid Oxide Fuel Cell,SOFC)的阳极材料,研究其在还原气氛中的析出及材料结构演变机理,探索其电化学性能及运行稳定性.实验结果表明,在经过在800℃还原2 h后,所有PSFR x样品的主要相结构都由ABO 3立方钙钛矿相转化为Ruddlesden-Popper(RP)层状钙钛矿相,同时在表面析出Fe-Ru合金纳米颗粒.XRD结果表明,少量的A缺位(x=0.1)可以抑制在还原过程中的杂相生成,保证了B位金属析出后A 2BO 4层状相的稳定性.随后,对SOFC进行的电化学性能测试,随着A缺位的增加,PSFR x的电化学输出性能随之先上升后下降,A缺位的最佳缺位比例为x=0.1.在800℃下,以PSFR 0.1为阳极的电解质支撑单电池在加湿H 2和C 3H 8的最大功率密度分别为0.747和0.528 W/cm^(2).进一步,在以C 3H 8为燃料气、恒电流为0.15 A/cm^(2)条件下对PSFR 0.1为阳极的单电池进行放电测试,实现了稳定的功率输出.

The(Pr_(0.5)Sr_(0.5))_(1-x)Fe_(0.9)Ru_(0.1)O_(3-δ)(PSFR x,x=0,0.1,0.2)perovskite oxides with different A-sites deficiency were prepared by combustion method and used as solid oxide fuel cell(Solid Oxide Fuel Cell,SOFC)anode materials.Experimental results show that,when reduced at 800℃for 2 h,the main phase structure of all PSFR x samples was transformed from ABO 3 cubic perovskite phase to Ruddlesden-Popper(RP)layered perovskite phase with Fe-Ru alloy nanoparticles precipitated on the surface.XRD results show that a small amount of A-site deficiency(x=0.1)can inhibit the generation of heterogeneous phases and guarantee the stability of the A 2BO 4 layered phase during the reduction process.Electrochemical performance tests of the single cells show that PSFR x electrochemical output performance rises first and then decreases with the increase of A-site deficiency content.The optimum content ratio of A-site deficiency is x=0.1.The maximum power density of single cell supported by electrolyte with PSFR 0.1 anode at 800℃in humidification H 2 and C 3H 8 is 0.747 and 0.528,respectively.Furthermore,the single cell shows a stability outputs at a constant current load of 0.15 A/cm^(2) in wet C 3H 8 fuels.