Enhancement of La0.6Sr0.4Co0.2Fe0.8O3-δ Surface Exchange through Ion Implantation

被引：24
作者：
Huang, Y. L. [1 ]
Pellegrinelli, C. [1 ]
Lee, K. T. [1 ,2 ]
Perel, A. [3 ]
Wachsman, E. D. [1 ]
机构：
[1] Univ Maryland, Energy Res Ctr, College Pk, MD 20742 USA
[2] Daegu Gyeongbuk Inst Sci & Technol, Dept Energy Syst Engn, Taegu, South Korea
[3] Appl Mat Inc, Varian Semicond Equipment, Gloucester, MA 01930 USA
来源：
JOURNAL OF THE ELECTROCHEMICAL SOCIETY | 2015年 / 162卷 / 09期
关键词：
ELECTRICAL-CONDUCTIVITY RELAXATION; OXYGEN REDUCTION; IN-SITU; CATHODE; COEFFICIENTS; DIFFUSION; TRANSPORT; ELECTROCHEMISTRY; TEMPERATURE; MECHANISMS;
D O I：
10.1149/2.1051508jes
中图分类号：
O646 [电化学、电解、磁化学];
学科分类号：
081704 ;
摘要：
La0.6Sr0.4Co0.2Fe0.8O3-delta (LSCF) has been demonstrated to be one of the best performing mixed ionic-electronic conductors (MIEC) for SOFC cathode materials. Surface exchange on LSCF, however, limits oxygen transport and performance. We investigated surface modified LSCF, by Mn ion implantation, for an enhanced surface oxygen exchange rate while maintaining LSCFs oxygen ion conductivity through the bulk. Various implantation energies and ion concentrations were used to create samples with different Mn-ion depth profiles. The oxygen transport properties, chemical diffusion coefficient (D-chem) and effective chemical surface exchange coefficient (k(chem)), were characterized by electrical conductivity relaxation (ECR), using DC four-point probe measurements during the oxygen re-equilibration process. The changes of k(chem) for different Mn doping levels and ion acceleration energies determined with ECR are compared with surface configurations obtained using X-ray photoelectron spectroscopy. The Mn ion implanted LSCF samples show an enhanced k(chem), improving the overall oxygen reduction reaction for the LSCF cathode material. possible factors for the increase in surface exchange for the Mn implanted LSCF samples are discussed. (C) 2015 The Electrochemical Society. All rights reserved.
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页码：F965 / F970
页数：6
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