氧化铈基电解质是中低温固体氧化物燃料电池最常用的材料之一。本研究利用密度泛函理论计算方法阐述了Li2O和CeO2分子之间的相互作用,计算结果表明Li2O对CeO2具有助烧作用。在此基础上,在氧化铈基电解质Gd0.1Ce0.9O1.95(GDC)中掺入不同比例(0~5mol%)Li2O,通过烧结曲线测试及扫描电镜分析了其实际烧结过程,并对其电化学性能进行了研究。实验结果表明,添加 Li2O后, GDC的烧结开始收缩温度明显向低温偏移,随掺杂量的增加,最大收缩速率的温度也逐渐降低,其中掺入2.5mol%Li2O-GDC在650℃就开始迅速收缩,900℃时相对致密度在99%以上；添加Li2O后, GDC总电导率提高,同时电池开路电压没有降低。因此, Li2O是一种很好的燃料电池氧化铈基电解质的助烧剂,具有很好的应用前景。
Cerium oxide-based materials are the most widely used electrolyte material for low-intermediate tem-perature Solid Oxide Fuel Cell (SOFC). In this study, the interaction between Li2O and CeO2 was calculated based on density functional theory (DFT). The results showed that the sintering of CeO2 was positively affected by Li2O. Based on this result, the actual sintering process of Gd0.1Ce0.9O1.95 (GDC) with different concentration (0–5mol%) of Li2O additive was characterized through the sintering behavior and scanning electron microscope (SEM). The elec-trochemical performance was also being investigated simultaneously. The results show that the initial shrinkage temperature shifted to lower temperature significantly, and the temperature of the highest shrinkage rate also decreased with the increasing of the Li2O additive content. The shrinking of GDC with 2.5mol%Li2O started at 650 ℃, and the GDC electrolyte with higher than 99%relative density was obtained at a low sintering temperature of 900 ℃. The total electrical conductivity of GDC was improved with Li2O additive. Meanwhile, the open circuit voltage of the corresponding single cell maintained nearly the same with pure GDC. These preliminary results indicate that Li2O is a very effective sintering aid for cerium oxide-based electrolyte in SOFC.
参考文献
- 下载量()
- 访问量()
- 您的评分：
-
10%
-
20%
-
30%
-
40%
-
50%