Fast ion-conductive electrolyte based on a doped LaAlO3 with an amorphous surface layer for low-temperature solid oxide fuel cells
Fast ion-conductive electrolyte based on a doped LaAlO3 with an amorphous surface layer for low-temperature solid oxide fuel cells
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DOI：
10.1016/j.jpowsour.2023.232723
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发表时间：
2023-03
影响因子：
9.2
通讯作者：
Dan Xu;A. Yan;Yang Yang-Yang;Shifeng Xu;Yongjun Zhou;Shuangjun Yang;Wen-Feng Lin
中科院分区：
文献类型：
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作者：
Dan Xu;A. Yan;Yang Yang-Yang;Shifeng Xu;Yongjun Zhou;Shuangjun Yang;Wen-Feng Lin
离子在固体氧化物电解质中的传输是先进的绿色能量转换装置如固体氧化物燃料电池（SOFC）中涉及的关键过程。常规SOFC电解质需要高操作温度（超过700 °C）以维持离子的相当大的体扩散和晶界扩散，从而实现足够的离子电导率以用于有效的燃料电池操作。本研究探索了一种新型的非晶/晶异质结构La 0·8 Sr 0·2Al 0·8 Zn 0·2 O3-δ（LSAZ）中的离子导电高速公路，它可以在相对较低的温度（450-550 °C）下提高SOFC中离子的迁移率。LSAZ异质结构包括绝缘钙钛矿核心和超离子传导非晶表面层。该电解质在550 °C下表现出0.319 S cm− 1的上级导电率，并且其用于SOFC中，该SOFC在550 °C下表现出1296 mW cm− 2的显著性能，这比在1400 °C下对LSAZ进行致密化10 h的SOFC高300倍。由高氧空位缺陷富集的超离子传导非晶表面层促进了沿LSAZ的纳米颗粒之间的晶界和界面的离子传导沿着。我们的发现提供了一种有效的方法来设计先进的高导电性电解质的固体氧化物燃料电池在降低的温度下运行。
Ion transport in solid oxide electrolytes is a key process involved in advanced green energy conversion devices such as solid oxide fuel cells (SOFCs). Conventional SOFC electrolytes require a high operational temperature (over 700 °C) to maintain considerable bulk and grain boundary diffusion of the ions to enable sufficient ionic conductivity for efficient fuel cell operation. The present study explores a novel ion conduction expressway in an amorphous/crystalline heterostructure, La0·8Sr0·2Al0·8Zn0·2O3-δ(LSAZ), which can boost the mobility of ions at a relatively low temperature (450–550 °C) for SOFCs. The LSAZ heterostructure includes an insulating perovskite core and a superionic-conducting amorphous surface layer. This electrolyte exhibits a superior conductivity of 0.319 S cm−1at 550 °C, and it is employed in a SOFC which demonstrates a remarkable performance of 1296 mW cm−2at 550 °C, which is 300 times higher than a SOFC with the LSAZ being densified at 1400 °C for 10 h. A superionic conducting amorphous surface layer enriched by high oxygen vacancy defects facilitates ionic conduction along the grain boundary and interfaces between the nanoparticles of LSAZ. Our finding provides an efficient way to design advanced highly conductive electrolytes for solid oxide fuel cells to be operated at reduced temperatures.