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A major challenge to overcome in demonstrating solid oxide fuel cells (SOFCs) to be suitable as efficient and environmentally friendly energy conversion devices capable of addressing pressing clean energy and environmental needs is to surmount chemical and thermo‐mechanical instabilities in their operational phase. To date, perovskite‐based mixed conducting cathodes, which include inherent Co and Sr elements for enhanced reactivity and conductivity, have been intensively studied. These Co/Sr‐based oxides, however, exhibit severe thermochemical expansion and suffer from Sr surface segregation, ultimately degrading the electrode performance. Here, high‐performance and durable SOFCs are demonstrated by employing a Co/Sr‐free fluorite‐based mixed conducting (Pr,Ce)O2‐δ (PCO) cathode eminently compatible with fluorite‐based solid electrolytes. The nanocolumnar PCO electrode developed in this study provides not only a remarkable low level of electrode resistance (e.g., ≈0.05 Ω cm2 at 600 °C) but also exceptional long‐term stability (e.g., a degradation rate 15 times slower compared to the state‐of‐the‐art La0.6Sr0.4CoO3‐δ perovskite). The competitive peak power densities of an anode‐supported single cell with the PCO cathode are also successively achieved, recording a value of 0.92 W cm−2 at 600 °C. These findings herald the development of new Co/Sr‐free electrodes for SOFCs at intermediate temperatures. [ABSTRACT FROM AUTHOR]

The electrocatalytic value of nanoparticles has attracted substantial attention in relation to energy conversion devices, including solid oxide fuel cells. Among various forms of analogs, ex‐solved metal nanoparticles originating from their parent oxides display strong particle‐substrate interactions and thus have the benefits of extended durability and of course enhanced catalytic activity. Inspired by recent advances, here, novel air‐electrode materials based on BaCoO3–δ perovskites decorated with socketed Ag nanoparticles are presented. Doping with niobium (Nb5+) and tantalum (Ta5+) can significantly promote the stability of the cubic perovskite phase. The developed oxides exhibit promising performance outcomes in the highly prized low‐to‐intermediate temperature regimes (450–650 °C). Moreover, the exclusion of Ag particles further activates the parent scaffold, thereby conveying record‐level area‐specific resistance (e.g., ≈0.02 Ω cm2 at 650 °C). Coupled with the unique nanoarchitecture, the newly designed cathode showcases in this study hold great promise for future air‐electrodes in fuel cells. [ABSTRACT FROM AUTHOR]

High-Performance and Durable Fuel Cells using Co/Sr-Free Fluorite-Based Mixed Conducting (Pr,Ce)O2- Cathode (Adv. (Pr,Ce)O2, Co/Sr-free mixed conducting oxides, nanocolumnar structures, oxygen reduction reaction, solid oxide fuel cells Keywords: (Pr,Ce)O2; Co/Sr-free mixed conducting oxides; nanocolumnar structures; oxygen reduction reaction; solid oxide fuel cells EN (Pr,Ce)O2 Co/Sr-free mixed conducting oxides nanocolumnar structures oxygen reduction reaction solid oxide fuel cells 1 1 1 11/21/22 20221117 NES 221117 B Fuel Cells b In article number 2202101, Ji-Won Son, WooChul Jung, and co-workers demonstrate high-performance and durable solid oxide fuel cells by employing a Co/Sr-free fluorite-based mixed conducting (Pr,Ce)O SB 2- sb cathode, delivering outstanding oxygen reduction reaction activity, importantly, together with a much extended long-term stability. [Extracted from the article]