Optimization and Stabilization of P-Type BISBTE/GRAPHENE Nanocomposites for Efficient Thermoelectric Energy Conversion

Abstract

The state-of-the-art Bismuth Antimony Telluride (BiSbTe) alloys have a promising potential to advance thermoelectric applications in energy harvesting for efficient power generation and active refrigeration. In this thesis, the combination of High-Energy Ball Milling and FAST/SPS Sintering Press showed a reliable and cost effective synthesis approach for artifact-free nanostructured bulk BiSbTe/Graphene nanocomposites. The results show successfulness in synthesizing homogenous elemental distribution and stable single phase of Bi0.4Sb1.6Te3 either in the pristine nanopowder or the multicomponent nanocomposites. It also confirms the crucial rule of graphene addition time on its structure, as well as, the morphology, mechanical behavior, and thermoelectric performance of the synthesized nanocomposites. The 5mins nanocomposite showed an ultrahigh micro-hardness of 1.78GPa, the highest power factor of 1.73mW/m.K2 at 323K, and the lowest thermal conductivity of 0.723W/m.K at 323K. This has resulted in its optimum Figure-of-Merit of 0.70 at 323K with 25% of improvements compared to the pristine BiSbTe.