Advanced LT-SOFC Based on Reconstruction of the Energy Band Structure of the LiNi0.8Co0.15Al0.05O2-Sm0.2Ce0.8O2-δHeterostructure for Fast Ionic Transport

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A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
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ACS Applied Energy Materials
Formation of a heterostructure of semiconductor materials is a promising method to develop an electrolyte with high ionic conductivity at low operational temperature of solid oxide fuel cells (LT-SOFCs). Herein, we develop various heterostructure composites by introducing a pure ionic conductor Sm0.2Ce0.8O2-δ (SDC) into a semiconductor LiNi0.8Co0.15Al0.05O2 (LNCA) for LT-SOFCs electrolyte. The morphology, crystal structure, elemental distribution, micro-structure, and oxidation states of the composite of LNCA-SDC are analyzed and studied via X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM), high resolution-transmission electron microscopy (HR-TEM), high energy dispersive spectrometry, and X-ray photoelectron spectroscopy (XPS). Electrochemical studies found that the optimal weight ratio of 0.5 LNCA-1.5 SDC heterostructure composite exhibits relatively high ionic conductivity (0.12 S cm-1 at 520 °C), which is much higher than that of SDC. The designed composite of LNCA-SDC heterostructures with optimal weight ratio (0.5:1.5) delivers a remarkable fuel cell power output of 0.735 W cm-2 at 520 °C. The formation of the heterostructure and reconstruction of energy bands at the interface play the crucial roles in enhancing ionic conduction to improve electrochemical performance. The prepared composite heterostructure delivers a unique and insightful strategy of electrolyte in advanced LT-SOFCs.
Funding Information: This study was supported by National Natural Science Foundation of China (NSFC) under grant no. 11674086, 11904088, and 2019CFB183. Scientific Research Project of Education Department of Hubei Province (no. Q20191010) and Research Project of Wuhan Science and Technology Bureau (no. 2019010701011394). Dr. Asghar thanks the Hubei Talent 100 program and Academy of Finland (Grant nos. 13329016, 13322738) for their support. Publisher Copyright: © 2021 The Authors. Published by American Chemical Society.
band bending, ionic conductivity, junction, low temperature, semiconductor electrolyte, semiconductor-ionic composite
Tayyab , Z , Rauf , S , Xia , C , Wang , B , Shah , M A K Y , Mushtaq , N , Liang , S H , Yang , C , Lund , P D & Asghar , M I 2021 , ' Advanced LT-SOFC Based on Reconstruction of the Energy Band Structure of the LiNi 0.8 Co 0.15 Al 0.05 O 2 -Sm 0.2 Ce 0.8 O 2-δ Heterostructure for Fast Ionic Transport ' , ACS Applied Energy Materials , vol. 4 , no. 9 , pp. 8922-8932 .