Li2CO3对锂氧化物电极SOFC电化学性能影响研究

The Effect of Li2CO3 on the Electrochemical Performance of SOFC with Lithium Compound Electrode

本文利用机械混合的方式将SrTiO 3与Li 2CO 3按照不同质量比混合制成了比例分别为95/5,90/10,70/30及100/0的STO-x%Li 2CO 3(x=0,5,10和30)复合电解质,并制备了结构为泡沫镍-Ni 0.8 Co 0.15 Al 0.05 LiO 2(NCAL)/STO-x%Li 2CO 3/NCAL-泡沫镍的单电池。在550℃、H 2/Air气氛中的燃料电池性能测试结果显示在SrTiO 3电解质中以机械混合的方式加入Li 2CO 3后电池的最大功率密度随着碳酸锂的添加量增加而降低,而且在电解质中没有混合Li 2CO 3的SrTiO 3电解质电池取得了最高的最大输功率密度,说明以机械混合的方式在SrTiO 3电解质中加入Li 2CO 3对这种新型结构SOFC的电化学性能没有提升作用。Ni-NCAL阳极在电化学性能测试过程中被还原生成的Li 2CO 3扩散到SrTiO 3电解质中形成的非晶层包覆在电解质颗粒表面对电解质离子电导率提升起到了关键作用。

In this paper,STO-x%Li 2CO 3(x=0,5,10 and 30)composite electrolytes were prepared by mixing SrTiO 3 and Li 2CO 3 at different mass ratios,and a single cell with foam nickel-Ni 0.8 Co 0.15 Al 0.05 LiO 2(NCAL)/STO-x%Li 2CO 3/NCAL-foam nickel was prepared.The electrochemical performance test results show that the maximum power density of the cell with STO-x%Li 2CO 3(x=0,5,10 and 30)composite electrolyte decreases with the increase of lithium carbonate,and the cell without Li 2CO 3 addition in the electrolyte achieves the highest maximum power density,which indicates that the addition of Li 2CO 3 in STO electrolyte by mechanical mixing has no effect on the electrochemical performance of this novel SOFC.Li 2CO 3 which diffused into the STO electrolyte from the NCAL electrode during the electrochemical performance test has the biggest influence on the ionic conductivity of the STO electrolyte.