Boride Based Electrode Materials with Enhanced Stability under Extreme Conditions for MHD Direct Power Extraction

 

(Left) Hexagonal crystal structure of ZrB<sub>2</sub> and HfB<sub>2</sub><br/>with a symmetry group P6/mmm; (right) Layered<br/>atomic arrangement of the diboride structures illustration
(Left) Hexagonal crystal structure of ZrB2 and HfB2
with a symmetry group P6/mmm; (right) Layered
atomic arrangement of the diboride structures illustration
Performer: 
Regents of the University of Idaho
Website:  Regents of the University of Idaho
Award Number:  FE0022988
Project Duration:  07/01/2014 – 06/30/2017
Total Award Value:  $399,938
DOE Share:  $399,938
Performer Share:  $0
Technology Area:  University Training and Research
Key Technology:  Innovative Energy Concepts
Location:  Moscow, Idaho

Project Description

In magneto-hydrodynamics (MHD) direct power extraction, a hot conducting combustion flame flows through a transverse magnetic field and current is directly extracted normal to the directions of both the flame flow and the magnetic field. The conductivity of the flame is increased by addition of potassium salts as seed. The operative conditions of the MHD ducts are very aggressive due to very high temperatures of the flame (~3000 K), high mass flow rate, and corrosive attack of the potassium salts. Therefore, the electrodes which extract current are exposed to very arduous conditions. Oxide based materials, such as strontium doped LaCrO3, have been considered candidate electrode materials for MHD power generation. These conventional oxide materials show high electrical resistivity, low thermal conductivity, and high volatility at MHD operating temperatures which limit their functionality. Therefore, development of next generation electrode materials that show high electrical and thermal conductivity infused with better stability in the aggressive high temperature environments is required.

Project Benefits

This project will lead to a better understanding of charge and mass transport behavior of transition metal borides and their oxidation kinetics in the presence of silicon and rare earth compounds. It will help develop ultrahigh temperature electrode materials for MHD direct power extraction applications with improved lifetimes.

Contact Information

Federal Project Manager 
Otis Mills: otis.mills@netl.doe.gov
Technology Manager 
Briggs White: briggs.white@netl.doe.gov
Principal Investigator 
Indrajit Charit: icharit@uidaho.edu
 

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