Operating Mechanism and Output Performance of Grid-Assisted Thermionic Energy Converter

With rising global energy demand and mounting environmental challenges, improving energy efficiency and developing clean energy conversion technologies have become critical research priorities. Thermionic energy converter (TEC) directly converts thermal energy into electricity with electrons as the working fluid, exhibiting a compact structure, simple operation, and high theoretical efficiency. However, the performance of TEC is severely limited by the space-charge barrier. Introducing a grid allows active regulation of interelectrode charge distribution, effectively mitigating this barrier. This study investigates the operating mechanism and output performance of the grid-assisted TEC. External electric-field regulation via the grid significantly enhances device performance. A theoretical model is established to analyze the effects of grid voltage and structural parameters on potential distribution, output power and efficiency. The influences of cathode work function, anode work function and cathode temperature are also examined. Results demonstrate that the grid structure suppresses the space-charge barrier and improves output power and efficiency, indicating its potential for high-performance energy conversion. This study offers theoretical guidance for the design and application of the grid-assisted TEC.