Research at LIMT is mainly focused on electronic ceramics and methods that apply in enhancing their primary characteristics. It all starts with the synthesis of new ceramic materials. Accordingly, the production of nanomaterials is leading to coatings application to the ceramic substrates. Finally, the performance of these novel materials is tested under various parameters of temperature, pressure and several atmospheres.
These new ceramics find further application in parts of SOFCs and in catalytic processes.
Sonochemical Synthesis of Metal–Organic Frameworks
Over the last 25 years, Metal–Organic Frameworks have been evolving as innovative materials. Their high surface area, crystallinity and chemical versatility make them promising materials for various applications such as gas adsorption/separation, catalysis, dye removal, membranes, etc. In our lab, we employ ultrasounds for the sonochemical synthesis of MOFs in order to achieve shorter reaction times, smaller particle size, phase-selectivity and desirable morphologies.
Advanced ceramics synthesis/characterization for use in Solid Oxide Fuel Cells (SOFC)
This is our main research activity. SOFCs are capable of direct electrochemical fuel (Η2, CH4, CH3OH) conversion to electricity. Advanced electroceramics are synthesised and characterised for use in SOFC implementations using traditional (sol-gel) and alternative (mechanochemical or sonochemical) methods. Different SOFC layering concepts are prepared (thin electrolyte on cathode, thin anode on electrolyte, etc.) and then investigated in terms of performance and durability on in-house equipment. The oxygen ions conductivity mechanism is also studied as it is a matter of high importance for the electrolyte materials. Recent projects have been focused on novel materials (apatites) that will be utilised in IT-SOFC applications.
Microbial Fuel Cells
Nanomaterials synthesis by sono-/electro-chemical and other methods
Nanoscale ceramic materials give us the potential to promote standalone or SOFC related catalysis reactions as well as sensors properties. The technologies that we are using for ceramic materials synthesis are: sol-gel, modified Pechnini (CA complexes), mechanochemical and sonochemistry (direct high energy ultrasound activity). On the other hand, nanometric metals, metal oxides and other more complex electroceramics are synthesized via sonochemistry, electrochemistry or their combination. All the techniques mentioned above are preferred as they require quite low levels of energy to be implemented.
Transport phenomena in condensed matter
The main research focus is on oxygen ions conducting ceramics used as SOFC electrolytes. Diffusion coefficients determination in bulk and across grain boundaries is implemented via tracing elements and rare isotopes self-diffusion techniques. Alternatively, bulk like cations are used as diffusion determinants. Secondary ion mass spectrometry (SIMS) is mainly used in determination of tracing elements concentration. In most of the cases, kinetic models are suggested.
It is a quick, accurate and productive method for thin films synthesis on various substrates. Originally, we have focused on ceramic oxygen barriers layering for C/C-Si-SiC composites shielding. Lately we are applying SOFC electrolyte materials (YSZ, GDC, LSGM) on porous ceramic cathodes or anodes.