Self‐Assembled Perovskite Nanocomposite With Beneficial Lattice Tensile Strain as High Active and Durable Cathode for Low Temperature Solid Oxide Fuel Cell

Abstract

The sluggish kinetics of oxygen reduction reaction (ORR) at low temperatures and the fast degradation of the cathode are the main obstacles to the commercialization of solid oxide fuel cells (SOFCs). However, it is still very challenging to achieve both high catalytic activity and favorable stability for single‐phase materials. Herein, a highly active and durable nanocomposite cathode (Ba0.5Sr0.5)0.75Pr0.25Co0.575Fe0.3W0.125O3‐δ (BSPCFW) for low‐temperature SOFC (≤650 °C) is presented, which self‐assembles into two cubic perovskites: the simple perovskite Pr0.38Ba0.25Sr0.37Co0.62Fe0.38O3‐δ (PBSCF‐c) and the B‐site cations ordered double perovskite Ba1.30Sr0.70Co1.0Fe0.25W0.75O6‐δ (BSCFW‐c). The former PBSCF‐c serves as the highly conductive and active catalyst for ORR, while the latter BSCFW‐c with a large lattice parameter introduces a key beneficial lattice tensile strain into the PBSCF‐c phase through a coherent interface, which significantly promotes the ORR activity at low temperatures with the area specific resistance of 0.034 Ω cm2 at 650 °C, and the long‐term stability of 2 years storage and 1280 h operation in symmetrical cell. The introduction of the beneficial lattice tensile strain in self‐assembled composite catalysts is an effective way to synergistically enhance the electrochemical activity and durability of the electrode materials for electrochemical devices.

Chlorine-Induced Surface Reconstruction of Perovskite Oxide Boosts Oxygen Evolution Reaction Activity

“…These outstanding properties were attributed to the well-controlled B-site metal ratio and large specific surface area of the PBSCF catalyst. 14,33,72 Herein, we report chlorine (Cl) doping of PBSCF perovskite oxide nanofibers synthesized by electrospinning. Electrochemical testing showed remarkable enhancements in OER activity and stability for the optimized chlorine-doped PBSCF (PrBa 0.5 Sr 0.5 Co 1.5 Fe 0. enhancing the OER performance of perovskite oxide through defect engineering and targeted surface modification.…”

“…The PrBa 0.5 Sr 0.5 Co 1.5 Fe 0.5 O 5+δ (PBSCF) catalyst using the nanospinning method exhibited excellent OER and oxygen reduction reaction (ORR) activities comparable to the noble metal RuO 2 catalyst. These outstanding properties were attributed to the well-controlled B-site metal ratio and large specific surface area of the PBSCF catalyst. ,, Herein, we report chlorine (Cl) doping of PBSCF perovskite oxide nanofibers synthesized by electrospinning. Electrochemical testing showed remarkable enhancements in OER activity and stability for the optimized chlorine-doped PBSCF (PrBa 0.5 Sr 0.5 Co 1.5 Fe 0.5 O 5– x +δ Cl x , where x = 0.1, 0.3, and 0.5, denoted as PBSCFCl0.1, PBSCFCl0.3, and PBSCFCl0.5).…”