Thermionic energy conversion (TEC) is the direct conversion of heat into electricity by the mechanism of thermionic emission, the spontaneous ejection of hot electrons from a surface in vacuum environment. There are two major obstacles for achieving highly efficient TECs; the strict need for low emitter and collector work functions, and the mutual repulsion of electron within the inter electrode gap, known as the space charge effect. Despite the aforementioned issues, TEC still remains an attractive approach to power generation. Like other direct energy conversion approaches, it requires no moving parts and thus has the potential for long lifetimes with little-to-no maintenance. In this project, we focuses on two sub-studies which are studying a mechanism of suppressing space charge problem and introducing nanostructures surface topography of low work function on anode/cathode materials for the enhancement of thermionic electrons emission. Based on the simulation work, a new concept for better performance TEC is proposed based on cylindrical configuration. With better heat transfer management, the concept offers approximately 15% better efficiency than the planar configuration. Silicon Carbide nanowires (SiC NWs) are successfully synthesized on the surface of the silicon substrate via a low-temperature (600 oc) synthesis method. . A total of —0.36 ev reduction of the effective work function has been achieved b as-s nthesized SiC NWs' thermionic cathode.
The study of direct thermal-to-electricity conversion using thermionic heat cell device_ Assoc Prof. Dr. Khairudin Mohamed