Recent development of ceria-based (nano)composite materials for low temperature ceramic fuel cells and electrolyte-free fuel cells

In the last ten years, the research of solid oxide fuel cells (SOFCs) or ceramic fuel cells (CFC) had focused on reducing the working temperature through the development of novel materials, especially the high ionic conductive electrolyte materials. Many progresses on single-phase electrolyte materials with the enhanced ionic conductivity have been made, but they are still far from the criteria of commercialization. The studies of ceria oxide based composite electrolytes give an alternative solution to these problems because of their impressive ionic conductivities and tunable ionic conduction behaviors. Significant advances in the understanding the ceria based composite material and construction of efficient fuel cell systems have been achieved within a short period. This report reviews recent developments of ceria-based composite from different aspects: materials, fundamentals, technologies, fabrication/construction parameters, electrochemistry and theoretical studies. Particular attention is given to ceria-carbonate (nano)composite, including its fuel cell performance, multi-ionic transport properties, advanced applications, corresponding electrode material and stability concerning. Besides, several novel fuel cell (FC) concepts like nanowire FC, all-nanocomposite FC and single-component/electrolyte-free fuel cell (SC-EFFC) are presented. This mini-review emphasizes the promise of ceria-based composites for advanced FC application and highlights the breakthrough of SC-EFFC research for high efficient energy conversion.

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Development of Ceria–salt composites with impressive ionic conductivity and tunable conduction behaviors is reviewed. ► Particular attention is given to ceria–carbonate composite, a promising electrolyte for LTCFC. ► Parameters affecting the electrical properties of ceria–carbonate composite are analyzed. ► Advanced applications, electrode materials and stability measurements development are presented. ► Novel fuel cell concepts and demonstrations such as EFFC are highlighted.