Simulation and analysis of the role of the electrodes in power degradation of alkali metal thermal to electric converter

Recently, much work has been done on the design of the Alkali Metal Thermalto-Electric Converter (AMTEC). One of the major problems yet to solve in AMTEC is its power degradation with time. During the extended testing of the AMTEC, maximum power output of the AMTEC was found to be decreasing from 2.45 W to 1.27 W after 18,000 hours of operation. Therefore, it is important to investigate and minimize the power degradation of AMTEC as much possible.

AMTEC uses TiN electrodes which degrade with time due to the grain growth and surface self-diffusion. In this project, the role of the electrode on the overall power degradation was investigated and reasons of the degradation were established qualitatively and quantitatively. The electrode was found 17% on average responsible for the overall degradation of power output. This work was also extended in finding possible remedies and modifications in the electrode material. Finally, RhW, and RhiW electrodes were found to be the better electrodes considering their improved grain growth and surface self-diffusion behavior.