In Situ Formation of Er0.4Bi1.6O3 Protective Layer at Cobaltite Cathode/Y2O3-ZrO2 Electrolyte Interface under Solid Oxide Fuel Cell Operation Conditions

Shuai He; Qi Zhang; Giulio Maurizio; Lorenzo Catellani; Kongfa Chen; Qibing Chang; Massimo Santarelli; San Ping Jiang

doi:10.1021/acsami.8b14026

In Situ Formation of Er_0.4Bi_1.6O₃ Protective Layer at Cobaltite Cathode/Y₂O₃-ZrO₂ Electrolyte Interface under Solid Oxide Fuel Cell Operation Conditions

ACS Appl Mater Interfaces. 2018 Nov 28;10(47):40549-40559. doi: 10.1021/acsami.8b14026. Epub 2018 Nov 15.

Authors

Shuai He¹, Qi Zhang^{1

2}, Giulio Maurizio^{1

3}, Lorenzo Catellani^{1

3}, Kongfa Chen², Qibing Chang⁴, Massimo Santarelli³, San Ping Jiang¹

Affiliations

¹ Fuels and Energy Technology Institute & Western Australian School of Mines: Minerals, Energy and Chemical Engineering , Curtin University , Perth , WA 6102 , Australia.
² College of Materials Science and Engineering , Fuzhou University , Fuzhou , Fujian 350108 , China.
³ Energy Department , Politecnico di Torino , Corso Duca degli Abruzzi 24 , 10129 Torino , Italy.
⁴ College of Materials Science and Engineering , Jingdezhen Ceramic Institute , Jingdezhen , Jiangxi 333403 , China.

PMID: 30394736
DOI: 10.1021/acsami.8b14026

Abstract

Bismuth-based oxides exhibit outstanding oxygen ionic conductivity and fast oxygen surface kinetics and have shown great potential as a highly active component for electrode materials in solid oxide fuel cells (SOFCs). Herein, a Nb-doped La_0.6Sr_0.4Co_0.2Fe_0.7Nb_0.1O_3-δ (LSCFNb) electrode with 40% Er_0.4Bi_1.6O₃ (ESB) composite electrode was successfully fabricated by decoration method and directly assembled on barrier-layer-free yttrium-stabilized zirconia (YSZ) electrolyte cells, achieving a peak power density of 1.32 W cm^-2 and excellent stability at 750 °C and 250 mA cm^-2 for 100 h. ESB decoration also significantly reduces the activation energy from 214 kJ mol^-1 for the O₂ reduction on pristine LSCFNb electrode to 98 kJ mol^-1. Further microstructural analysis reveals that there is a redistribution and migration of the ESB phase in the ESB-LSCFNb composite toward the YSZ electrolyte under the influence of cathodic polarization, forming a thin ESB layer at the cathode/YSZ electrolyte interface. The in situ formed ESB layer not only prevents the direct contact and subsequent reaction between segregated SrO and YSZ electrolytes, but also remarkably promotes the oxygen migration/diffusion at the interface for O₂ reduction reaction, resulting in a remarkable increase in power output and a decrease in activation energy. The present study clearly demonstrated the in situ formation of a highly functional and active ESB protective layer at LSCFNb cobaltite cathode and YSZ electrolyte interface via ESB-decorated LSCFNb composite cathode under SOFC operation conditions.

Keywords: ESB-LSCFNb composite cathode; decoration; direct assembly; electrode/electrolyte interface; in situ formation of ESB interlayer; solid oxide fuel cells.