About this Research Topic
The generation of power with reduced or zero-emission has become very crucial. Fuel cell technology is mature and ready to offer many advantages, including heat and power generation, with high efficiency compared to conventional technologies, to be used as a polygeneration system. Among them, Molten Carbonate Fuel Cells (MCFCs), Solid Oxide Fuel Cells (SOFCs), and High-Temperature Proton Exchange Fuel Cells (HT-PEMFCs) are very suitable because they offer high system efficiency, fuel flexibility, and power generation in stationary, distributed, or transportation applications. The critical components of these fuel cells determine their operating temperatures, efficiency, durability, and costs.
For SOFCs, the critical component is usually the electrolyte material, such as yttrium stabilized zirconia (YSZ), gadolinium doped ceria (GDC), and their related and modified systems. High sintering and operating temperatures are required to ensure sufficient ionic conductivity through the electrolyte. Such high temperatures can lead to the coarsening of the Nickel electro-catalyst in the anode and thermal stress in the cell structure, causing physical defects, the increase in manufacturing and operating costs. Therefore, research is focused on new ceramic materials to reduce operative temperature without affecting electrochemical properties. For MCFCs, the ion-conducting molten salt electrolyte is based on Li/K carbonates, supported by a matrix, usually a lithiated Al-based oxide. Similarly to SOFCs, coarsening, thermal degradation, and structural changes affect the durability of the device, due to the electrolyte evaporation, leakage, and corrosive nature. Hence, less aggressive, conducting, and durable electrolyte and matrix materials, together with in-operando refilling approach, are needed to reduce costs, maintenance, losses. HT-PEMFCs are best to be applied in transportation and other small and portable applications due to the high energy and volume density, and the operating temperature range. The critical component is the membrane-electrode assembly (MEA), and this complex component include anode, cathode, and proton exchange membrane, together with catalyst layers and their assembly and fabrication processes. All these factors contribute to the costs, efficiency, and durability of the whole device, and research in materials is needed to optimize and maximize them.
This Research Topic aims to cover promising and recent research trends in the field of electrolytes, membranes, electrocatalysts, strategies, fabrication processes and material economy for these classes of fuel cells, by investigating novel materials and synthesis methods, and correlating the chemical, microstructural and structural features with electrochemical behavior and performance. The articles published in this Research Topic will contribute to define the state-of-the-art of best performing materials in polygeneration applications. Manuscripts on carbon, ceramic, polymer, alloys, carbonates, doped and multi-doped materials, with the relationship between composition, microstructure, electrochemical, and catalytic properties, together with performance, feasibility and sustainability studies are welcome.
Areas to be covered in this Research Topic include, but are not limited to:
- Synthesis of new materials or improvement of existing material properties by preparation and/or fabrication;
- Electrochemical characterizations;
- New fabrication procedures;
- Evaluation of cell performances under hydrogen or other relevant fuels;
- Catalytic activity under internal reforming in high-temperature fuel cells.
Keywords: electrolytes, ionic conductivity, SOFCs, MCFCs, PEMFCs
Important Note: All contributions to this Research Topic must be within the scope of the section and journal to which they are submitted, as defined in their mission statements. Frontiers reserves the right to guide an out-of-scope manuscript to a more suitable section or journal at any stage of peer review.