主題：Polymer-Derived Ceramics: Sustainable Materials for Energy
Conversion and Storage
內容簡介：Two PDC classes capable to be operated at ultrahigh temperatures (i.e., T beyond 1500 °C) as well as their potential for the fabrication of thermal barrier coatings (TBCs) and environmental barrier coatings (EBCs) will be presented. Firstly, substrate materials based on the Mo-Si-B (molybdenum silicide boride) intermetallic system will be introduced, which exhibit improved UHT behavior with respect to the state-of-the-art Ni-base superalloys. Beside details on their preparation, physical and thermomechanical properties thereof will be presented. Furthermore, the synthesis and the UHT behavior of Si?Hf?C?X-based (X = O, N, B) ceramic nanocomposites will be discussed as novel candidate materials for top coats used in TBC applications in comparison to the zirconia-based state?of?the?art coatings. Information on the processing of the two material classes to produce TBC / EBC systems will be also provided. PDC method also is demonstrated a cost-effective synthesis route for coated highly porous Si that is simple to implement and provides Si-based anode materials with capacities between 2000 and 3000 mAhg-1, Coulombic efficiencies above 99.5 %, and almost 100 % capacity retention over more than 100 cycles. The Si-based composite is prepared from porous silicon (obtained by reduction of silica) by encapsulation in an organic carbon and polymer-derived siliconoxycarbide (C/SiOC) matrix.