BPN835: Silicon Carbide Passivated Electrode for Thermionic Energy Conversion


In thermionic energy converters (TECs), electrons emitted from a hot electrode (emitter) into a vacuum gap are harvested by a cooler electrode (collector), and then return to the emitter, delivering power to an external load. In this process, TECs convert heat directly into electricity and have the potential to achieve high efficiencies comparable to those of conventional heat engines. We have initiated a collaborative project to develop a microfabricated, close-gap thermionic energy converter that utilizes heat from a combustion source. Potential applications include residential combined heat and power systems and light-weight battery alternatives. One key challenge is designing the emitter, which needs to be highly conductive and survive temperatures as hot as 1700 °C in an oxidizing environment. While tungsten is an attractive choice for the emitter, it readily oxidizes under the envisioned conditions. Owing to its chemical inertness and mechanical strength at high temperatures, silicon carbide is an effective option for electrode passivation. In this work, we are developing processes for fabricating a SiC- protected tungsten electrode, exploring the necessity and effectiveness of various interdiffusion barriers, and investigating its long-term stability under harsh environments.

Project end date: 01/28/19

Steven R. DelaCruz
Zhongtao Wang
Publication date: 
July 30, 2018
Publication type: 
BSAC Project Materials (Final/Archive)
PREPUBLICATION DATA - ©University of California 2018

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