Enhancing the oxygen reduction reaction activity and durability of a double-perovskite via an A-site tuning  

通过A位调控强化双钙钛矿氧还原反应活性及稳定性

作　　者：Feng Zhu Fan He Kang Xu Yu Chen 朱峰;何帆;徐康;陈宇(School of Environment and Energy,South China University of Technology,Guangzhou 510006,China;Guangdong Provincial Key Laboratory of Atmospheric Environment and Pollution Control,South China University of Technology,Guangzhou Higher Education Mega Centre,Guangzhou 510006,China)

机构地区：[1]School of Environment and Energy,South China University of Technology,Guangzhou 510006,China [2]Guangdong Provincial Key Laboratory of Atmospheric Environment and Pollution Control,South China University of Technology,Guangzhou Higher Education Mega Centre,Guangzhou 510006,China

出　　处：《Science China Materials》2022年第11期3043-3052,共10页中国科学（材料科学（英文版）

基　　金：supported by the National Natural Science Foundation of China(22179039 and 22005105);the Pearl River Talent Recruitment Program(2019QN01C693 and 2021ZT09L392);the Natural Science Foundation of Guangdong Province(2021A1515010395)。

摘　　要：The major factors limiting the electrochemical performance of a perovskite cathode for ceramic-based fuel cells are the sluggish oxygen reduction reaction(ORR)kinetics and poor durability,which are largely determined by the Asite elements.In this work,to enhance the ORR activity and stability,we present an effective strategy of tuning the A-site dopant in a layered double perovskite oxide of Ba_(0.8)Gd_(0.8)Pr_(0.4)-Co_(2)O(6-δ)(BGPC).When applied as a cathode on a La_(0.8)Sr_(0.2)-Ga_(0.8)Mg_(0.2)O_(3-δ)(LSGM)electrolyte-supported cell,it demonstrates high electrochemical performance,achieving an areaspecific resistance(ASR)of 0.170Ωcm^(2),and a peak power density(PPD)of 1.189 W cm^(-2)at 800℃,better than those acquired from a state-of-the-art(La_(0.6)Sr_(0.4))_(0.95)Co_(0.2)Fe_(0.8)O_(3-δ)(LS95 CF)-based cathode.The single cells with the BGPC cathode exhibit better performance and stability(a degradation rate of 0.074%h^(-1))than the cells with the LS95 CF cathode(a PPD of 1.079 W cm^(-2)at 800℃and a degradation rate of0.13%h^(-1))under the same operating conditions.By the electrochemical performance evaluation and characterizations,it is suggested that A-site tuning on a double-perovskite oxide can be a promising strategy to enhance the electrode activity and durability of fuel cells.制约陶瓷基燃料电池钙钛矿阴极的电化学性能的主要因素是其缓慢的氧还原反应(ORR)动力学和较差的稳定性.这两个性能的好坏在很大程度上取决于钙钛矿基阴极材料的A位元素.因此,在本工作中,我们提出一种双钙钛矿氧化物Ba_(0.8)Gd_(0.8)Pr_(0.4)Co_(2)O_(6-δ)(BGPC)的A位元素调控策略,显著提高BGPC的ORR活性和稳定性.作为La_(0.8)Sr_(0.2)Ga_(0.8)Mg_(0.2)O_(3-δ)电解质支撑的单电池阴极材料时,BGPC表现出优异的电化学活性和稳定性.比如,在800℃时,电极的面积比电阻为0.170Ωcm^(2),并且电池的峰值功率密度达到1.189 W cm^(-2),优于目前商业化的(La_(0.6)Sr_(0.4))_(0.95)Co_(0.2)Fe_(0.8)O_(3-δ)(LS95CF)阴极的性能(峰值功率密度为1.079 W cm^(-2)).此外,在0.5 A cm^(-2)的恒流工作模式下,使用BGPC作为阴极的单电池稳定性(衰减速率为0.074%h-1)优于使用LS95CF阴极的单电池(衰减速率为0.13%h^(-1)).优异的电化学性能和良好的稳定性,表明钙钛矿材料的A位调控是提高电极电化学活性和稳定性的一种有效策略.

关 键 词：A-site tuning double perovskite oxygen reduction reaction DURABILITY 

分 类 号：TM911.4[电气工程—电力电子与电力传动] TB34[一般工业技术—材料科学与工程]