摘要
固体氧化物电池可实现CO/CO_(2)的可逆转化,在电能和化学能相互转化过程中显示出巨大潜力.然而,其商业化进展一直受到燃料极抗积碳性能差的限制.本工作中,我们发展了一种CoFe合金纳米颗粒和Ruddlesden-Popper层状结构Sr_(3)Fe_(1.25)Mo_(0.75)O_(7)-δ复合新型燃料电极(CoFe-SFM),其可以通过钙钛矿Sr_(2)Fe_(7/6)Mo_(0.5)Co_(1/3)O_(6-δ)在还原气氛中退火发生相变得到.电化学阻抗谱和弛豫时间分步法分析可知CoFe-SFM电极通过改善体相氧化学扩散能力和表面氧交换过程来增强CO氧化和CO_(2)还原动力学.在固体氧化物燃料电池模式下,800℃的最大功率达到259 mW cm^(-2);在固体氧化物电解电池模式下,1.3 V工作电压下单电池的电解电流密度为-0.453 A cm^(-2),都远超对比电极材料.在20次SOFC-SOEC循环操作条件下,CoFe-SFM燃料极依然保持稳定的微结构和抗积碳性能,电池性能保持良好.该工作可为CO_(2)转化、抗积碳电极材料设计和提升电极表界面反应动力学提供一定的指导作用.
The reversible solid oxide cell(RSOC)is an attractive technology to mutually convert power and chemicals at elevated temperatures.However,its development has been hindered mainly due to the absence of a highly active and durable fuel electrode.Here,we report a phase-transformed CoFe-Sr_(3)Fe_(1.25)Mo_(0.75)O_(7)-δ(CoFe-SFM)fuel electrode consisting of CoFe nanoparticles and Ruddlesden-Popper-layered Sr_(3)Fe_(1.25)Mo_(0.75)O_(7)-δ(SFM)from a Sr_(2)Fe_(7/6)Mo_(0.5)Co_(1/3)O_(6)-δ(SFMCo)perovskite oxide after annealing in hydrogen and apply it to reversible CO/CO_(2)conversion in RSOC.The CoFeSFM fuel electrode shows improved catalytic activity by accelerating oxygen diffusion and surface kinetics towards the CO/CO_(2)conversion as demonstrated by the distribution of relaxation time(DRT)study and equivalent circuit model fitting analysis.Furthermore,an electrolyte-supported single cell is evaluated in the 2:1 CO-CO_(2)atmosphere at 800℃,which shows a peak power density of 259 mW cm^(-2)for CO oxidation and a current density of-0.453 A cm^(-2)at 1.3 V for CO_(2)reduction,which correspond to 3.079 and3.155 m L min-1cm^(-2)for the CO and CO_(2)conversion rates,respectively.More importantly,the reversible conversion is successfully demonstrated over 20 cyclic electrolysis and fuel cell switching test modes at 1.3 and 0.6 V.This work provides a useful guideline for designing a fuel electrode through a surface/interface exsolution process for RSOC towards efficient CO-CO_(2)reversible conversion.
作者
李一航
Manish Singh
庄泽超
景义甫
李凤姣
Kristina Maliutina
何传新
范梁栋
Yihang Li;Manish Singh;Zechao Zhuang;Yifu Jing;Fengjiao Li;Kristina Maliutina;Chuanxin He;Liangdong Fan(College of Chemistry and Environmental Engineering,Shenzhen University,Shenzhen 518060,China;College of Physics and Optoelectronic Engineering,Key Lab of Optoelectronic Devices and Systems of Ministry of Education/Guangdong Province,Shenzhen University,Shenzhen 518060,China;Department of Chemistry,Division for Pure and Applied Biochemistry,Naturvetarvägen 14,22362,Lund University,Sweden;Department of Chemistry,Tsinghua University,Beijing 100084,China;Shenzhen Key Laboratory of New Lithium-ion Batteries and Mesoporous Materials,Shenzhen University,Shenzhen 518060,China)
基金
financially supported by the National Natural Science Foundation (52002249,51402093 and 21706162)
Guangdong Basic and Applied Basic Research Foundation (2019A1515110025 and 2017A 030313289)
the Research Grant for Scientific Platform and Project of Guangdong Provincial Education Office (2019KTSCX151)
China Postdoctoral Science Foundation (2020M682872)
Shenzhen Government’s Plan of Science and Technology (JCYJ201803005125247308)
Technical support from the Instrumental Analysis Center of Shenzhen University (Xili Campus) is also appreciated。
