Tailoring defect chemistry at interfaces for promoted oxygen reduction reaction kinetics

Abstract

The engineering of the defect concentration and distribution at the interface between the electrolyte and the cathode of intermediate temperature-solid oxide fuel cells (IT-SOFCs) is important because the oxygen reduction...

Precursor‐driven facile densification of Gd 0. 1 Ce 0 . 9 O 2− δ interlayer for high‐performance solid oxide fuel cells

“…However, their performance 4 and durability 5‐7 over the long‐term operation, which are directly associated with system costs, remain a challenge for wider commercial applications. Among the various candidates of electrolyte for SOFCs, yttria‐stabilized zirconia (YSZ) is the most commonly used electrolyte material that demonstrates reasonable ionic conductivity and structural robustness 8,9 . However, the interface characteristics between the YSZ electrolyte and cathode still require further improvements to achieve high performance and stability 10 .…”

“…However, the interface characteristics between the YSZ electrolyte and cathode still require further improvements to achieve high performance and stability 10 . First, the insufficient number of oxygen vacancies for the oxygen reduction reaction (ORR) at the YSZ surface induces sluggish oxygen incorporation and oxygen transfer at triple phase boundaries (TPBs), where the YSZ electrolyte, cathode, and oxygen gas meet, leading to a significant drop in performance at lower operating temperatures 8,11 . Second, chemical intermixing at the interface between the YSZ electrolyte and Sr‐based perovskite cathode generates insulating by‐products such as SrZrO 3 and La 2 ZrO x during long‐term operation, thereby deteriorating oxygen dissociation, oxygen incorporation, and oxide ion transfer 12,13 …”

“…10 First, the insufficient number of oxygen vacancies for the oxygen reduction reaction (ORR) at the YSZ surface induces sluggish oxygen incorporation and oxygen transfer at triple phase boundaries (TPBs), where the YSZ electrolyte, cathode, and oxygen gas meet, leading to a significant drop in performance at lower operating temperatures. 8,11 Second, chemical intermixing at the interface between the YSZ electrolyte and Sr-based perovskite cathode generates insulating by-products such as SrZrO 3 and La 2 ZrO x during long-term operation, thereby deteriorating oxygen dissociation, oxygen incorporation, and oxide ion transfer. 12,13 To overcome these limitations, a Gd 0.1 Ce 0.9 O 2Àδ (gadolinia doped ceria [GDC]) interlayer between the YSZ electrolyte and cathode has been widely employed owing to its higher ionic conductivity 14 and better chemical compatibility without the generation of by-products at the interface during long-term operation.…”

Complexions at the Electrolyte/Electrode Interface in Solid Oxide Cells

“…Multiple studies have investigated the macroscopic properties of the YSZ/LSM interface, focusing on the influence of the preparation method, oxygen content, polarization and aging on resistance, [ 10,11 ] reaction kinetics [ 12 ] and the formation of inactive pyrochlore layers. [ 13,14 ] On the mesoscale, the formation of micropores and ring‐shaped contact craters of YSZ and long range Mn and La segregation have been described.…”

High‐dispersion Co‐Fe‐NC electrocatalyst based on leaf‐shaped zeolite imidazole framework for oxygen–reduction reaction in acidic medium

“…The oxygen-reduction reaction (ORR), one of the critical reactions of energy conversion during electrocatalytic reactions, has received considerable attention over the last decade. [1][2][3][4][5] In particular, Pt-based catalysts, which are the only commercial ORR catalysts for fuel cells, exhibit high catalytic activity. 6 However, they suffer from low stability, high price, and local ubiquity issues.…”