제목 : First-principles simulations for materials in applications of energy conversion and storage

일시 : 2010년 7월 29일(목) , 4:00  p.m.

장소 : 301동 1512-1호

연사 : 박민식 박사 (삼성종합기술원)

내용 :  

 Recently, the world-wide demand for the renewable and green energy has been increasing, since the problems of limited reserve of fossil fuels and global warming become worse. To establish such an alternative energy system, the novel technologies of energy generation, conversion, storage should be developed, in which the study of materials is particularly fundamentals, since such energy phenomena occur efficiently in materials. In the materials research, accompanied with experiments, the rapid development of simulation tools, especially first-principles simulations, and computational ability by supercomputers plays a very important role in designing more efficient energy materials. In this presentation, I will introduce simulation results by the first-principles calculations for the energy conversion and storage materials. For energy conversion materials, thermoelectric transport properties in p-type Bi and Sb tellurides will be discussed by the analysis of calculated Seebeck coefficient and electrical conductivity, in which we found electronic structure characteristics and volume have influence on the thermoelectric properties in the materials. For the energy storage, first, hydrogen storage materials of Mg, Al metals and binary MgH2 insulator will be discussed. Through the study of formation and migration of the hydrogen impurities and related native point defects, the role of interaction between hydrogen impurities and vacancies for the hydrogen storage will be discussed in Mg and Al metals. Furthermore, in MgH2, we found the important role of charged states of native point defects in the hydrogenation and dehydrogenation kinetics. Second, the Li ion storage materials comprised in the cathode and anode of a rechargeable battery system will be introduced. Especially, in the aspects of energy capacity and safety, some issues, such as structural and thermal stability of transition metal oxides (cathode) and dendrite formation on the Li metal surface (anode), will be discussed.