Nanocomposite Electrodes as a New Opportunity to Transform the Performance of Solid Oxide Cells

Solid Oxide Cells (SOCs) are poised to serve as economically vital, high-efficiency energy conversion devices. But certain critical issues persist in their current stage of development, including system aging during high temperature operation, or reduced performance at low temperature running. To tackle these challenges and drive the advancement of SOC technology, nanocomposite electrodes have emerged as a promising and revolutionary solution to provide high performance and durability at the same time. Persistent efforts have been dedicated to the development of novel nanocomposite electrodes and unraveling the underlying working mechanisms of nanostructured heterogeneous electrodes. These advancements are fueled by the remarkable enhancements that nanocomposites offer, not only in terms of ionic and/or electronic conductivity but also in electrocatalytic activity and stability for SOC. Both experimental results and theoretical calculations validate these enhancements, making nanocomposites an attractive avenue for exploration. To summarize the recent advancements and provide a forward-looking insight regarding this field in this review, we (1) start with an overview of the progress in the development of nano-scaled composite electrodes, encompassing both oxygen ion conducting and proton conducting systems, (2) then highlight the unique attributes of nanocomposite electrodes in the enhancement of the SOC performance, (3) delve into the various techniques used to fabricate nanocomposite electrodes with precise control over their composition, structure, and morphology, and (4) finally acknowledge these remaining obstacles and take a critical look at the hurdles that need to be overcome. Alongside identifying these challenges, we propose potential strategies and research directions to address them effectively. By bridging the gap between current research progress and future possibilities, we aspire to inspire further exploration and innovation in electrochemical energy conversion systems.