A novel core-shell LSCF perovskite structured electrocatalyst with local hetero-interface for solid oxide fuel cells. (14th April 2020)

• Record Type: Journal Article
• Authors: Wang, Liang; Wang, Piaopiao; Geng, Chaoliang; Cao, Hang; Xu, Chenxi; Cheng, Jigui; Hong, Tao
• Is Part Of: International journal of hydrogen energy. Volume 45:Number 20(2020)
• Page Start: 11824
• Page End: 11833
• Publication Date: 2020-04-14
• Subjects: Core-shell -- Surface coating -- Oxygen reduction reaction -- Lattice mismatch; Hydrogen as fuel -- Periodicals; Hydrogène (Combustible) -- Périodiques; Hydrogen as fuel; Periodicals; 665.81
• DOI: 10.1016/j.ijhydene.2020.02.130
• Languages: English
• ISSNs: 0360-3199

Abstract

Abstract: In this work, a La0.6 Sr0.4 Co0.2 Fe0.8 O3-δ (LSCF113 ) perovskite core coated by Ruddlesden-Popper phase La0.6 Sr1.4 Co0.2 Fe0.8 O4-δ (LSCF214 ) thin film to form a LSCF113-214 core-shell structure cathode is synthesized by Sr 2+ solution coating method. Its phase composition, lattice structure, electrochemical catalytic activity and full cell performance are investigated. The electrocatalytic activity and stability of the LSCF113 cathode are enhanced by in situ formation of LSCF214 on the LSCF113 surface. The electrochemical performance enhancement is due to the higher catalytic activity of the LSCF214 Ruddlesden-Popper phase and the mismatch of the lattice parameters between the LSCF214 and LSCF113 regions leading to more favorable oxygen vacancy formation and oxygen molecule adsorption. The electrochemical impedance spectrum indicates that LSCF113-214 electrode has a lower polarization resistance (0.17 Ωcm 2 ) than the LSCF113 electrode (0.32 Ωcm 2 ) at 650 °C. And the long term stability of LSCF113-214 is evaluated with no structure evolution in 400 h test at 600 °C. An anode-supported single cell with doped ceria as the electrolyte is used to evaluate the electrochemical performance of LSCF113-214, which shows an open circuit voltage of 0.81 V and a maximum power density of 0.57 W cm −2 at 650 °C. Highlights: A cathode with LSCF214 as shell and LSCF113 as core was synthesized. The electrochemical catalytic activity of LSCF113 was greatly enhanced by LSCF214 . The LSCF113-214 core-shell electrode exhibited an excellent long term stability.