Study on charge transportation in the layer-structured oxide composite of SOFCs. (12th July 2018)

• Record Type: Journal Article
• Authors: Liu, Xueqi; Dong, Wenjing; Xia, Chen; Huang, Qiuan; Cai, Yixiao; Wei, Lili; Wu, Guitai; Wang, Xunying; Tong, Yuzhu; Qiao, Zheng; Meng, Yuanjing; Mushtaq, Naveed; Wang, Baoyuan; Wang, Hao
• Is Part Of: International journal of hydrogen energy. Volume 43:Number 28(2018)
• Page Start: 12773
• Page End: 12781
• Publication Date: 2018-07-12
• Subjects: Charge carrier transportation -- Semiconductor-ionic conductor -- Hybrid O2−/H+ conduction -- Low-temperature SOFC; Hydrogen as fuel -- Periodicals; Hydrogène (Combustible) -- Périodiques; Hydrogen as fuel; Periodicals; 665.81
• DOI: 10.1016/j.ijhydene.2018.03.227
• Languages: English
• ISSNs: 0360-3199

Abstract

Abstract: In the past few years, triple (H + /O 2− /e − ) conducting materials have been regarded as one of the most promising electrode categories for solid oxide fuel cells (SOFCs). In this work, a layer-structured LiNi0.8 Co0.15 Al0.05 O2-δ (LNCA) with triple conduction has been studied. The semiconductor-ionic conductor (SIC) LNCA-SDC composite has been fabricated by compositing the LNCA material with ionic conductor, i.e., samarium doped ceria (SDC). The electrochemical performance of the LNCA-SDC composite was studied by electrochemical impedance spectroscopy, while its electronic conductivity was confirmed by d.c. polarization method. It is found that the ionic conductivity of the composite is higher than the electronic conductivity by several orders of magnitude. The charge carriers and transportation properties of LNCA-SDC were studied using H + and O 2− blocking layer cells respectively. Results prove that the LNCA-SDC composite is a hybrid oxygen ion-proton conducting material. The oxygen ion conduction is dominated at low temperature (425–500 °C), however, it is comparable with H + conduction at high temperature (550 °C). Additionally, the formation of Li2 CO3 under fuel cell operation environment was observed and the mechanism of the hybrid conductivity of LNCA-SDC was studied. Highlights: The electrical conductivities of LNCA and LNCA-SDC composite are studied. Different electrical properties of the LNCA-SDC are observed in fuel cells. The total conductivity of LNCA-SDC composite is dominated by ionic conductivity. Hybrid O 2− and H + conduction in LNCA-SDC. Hybrid ionic conductive behavior analysis for LNCA-SDC.