2 research outputs found
Electrochemically Assisted Construction of a La<sub>2</sub>NiO<sub>4+δ</sub>@Pt Core–Shell Structure for Enhancing the Performance and Durability of La<sub>2</sub>NiO<sub>4+δ</sub> Cathodes
Ruddlesden–Popper oxide La2NiO4+δ (LNO) has a high ionic conductivity and good thermal
match with
the electrolyte of solid oxide fuel cells (SOFCs); however, LNO suffers
from performance decay owing to the La surface segregation under the
operation conditions of SOFCs. Herein, we report an in situ electrochemical
decoration strategy to improve the electrocatalytic activity and durability
of LNO cathodes. We show that the electrochemical polarization leads
to in situ construction of the LNO@Pt core–shell structure,
significantly suppressing the detrimental effect of La surface segregation
on the LNO cathode. The initial peak power density of a single cell
with the LNO cathode is 0.71 W cm–2 at 750 °C,
increasing to 1.39 W cm–2 by the in situ construction
of the LNO@Pt core–shell structure after polarization at 0.5
A cm–2 for 20 h. The LNO@Pt core–shell structure
is also highly durable without noticeable performance degradation
over the duration of the test for 180 h. The findings shed light on
the design and fabrication of highly active and durable LNO-based
cathodes for SOFCs
Ultrafine, Dual-Phase, Cation-Deficient PrBa<sub>0.8</sub>Ca<sub>0.2</sub>Co<sub>2</sub>O<sub>5+δ</sub> Air Electrode for Efficient Solid Oxide Cells
Nanostructured air electrodes play a crucial role in
improving
the electrocatalytic activity of oxygen reduction and evolution reactions
in solid oxide cells (SOCs). Herein, we report the fabrication of
a nanostructured BaCoO3-decorated cation-deficient PrBa0.8Ca0.2Co2O5+δ (PBCC)
air electrode via a combined modification and direct assembly approach.
The modification approach endows the dual-phase air electrode with
a large surface area and abundant oxygen vacancies. An intimate air
electrode–electrolyte interface is in situ constructed with the formation of a catalytically active Co3O4 bridging layer via electrochemical polarization.
The corresponding single cell exhibits a peak power density of 2.08
W cm–2, an electrolysis current density of 1.36
A cm–2 at 1.3 V, and a good operating stability
at 750 °C for 100 h. This study provides insights into the rational
design and facile utilization of an active and stable nanostructured
air electrode of SOCs