Novel carbon-ion fuel cells. Final report, October 1, 1993--September 30, 1996

Technical Report · Wed Jan 01 04:00:00 EST 1997

DOI:https://doi.org/10.2172/475616· OSTI ID:475616

Cocks, F H

Mixed lanthanide dicarbides having the fluorite crystal structure have been synthesized using the elemental lanthanide metals and elemental carbon that was 99.9% pure carbon-13 isotope. A two step process of first, arc furnace melting of the components, followed by an annealing step in a high vacuum furnace, was adopted as the standard method of fabricating small cast ingots of the dicarbides. The crystal structure of the various lanthanide dicarbides produced were confirmed by x-ray diffraction under protective atmospheres at both room temperature at Duke University and at high temperature at Oak Ridge National Laboratory. After more than 15 combinations of cerium or lanthanum with dopants were tried, low temperature x-ray diffraction showed that Ce{sub .5}Er{sub .5}C{sub 2} had been successfully stabilized and had the desired fluorite crystal structure at room temperature. The fluorite crystal structure lanthanide dicarbide cast ingots were further prepared by having flat and clean surfaces ground onto their surfaces by high-speed milling machines inside argon gas atmosphere gloveboxes. The surfaces thus created were then coated with carbon-12 by the arc evaporation method under low pressure argon gas. The coated ingots were then allowed to have carbon diffusion occur from the surface coating of carbon-12 into the ingot of dicarbide that had been synthesized from carbon-13. After the diffusion run, the cast ingots were slit down the axis perpendicular to the carbon coating. The fracture surface created was then squared and polished by high,speed milling in a glove box with a argon atmosphere. The high diffusion co-efficient of carbon in lanthanide dicarbides having the fluorite crystal structure would make possible the manufacture of a carbon-ion electrolyte for use in a battery or a fuel cell that could consume solid carbon as it`s feedstock.

• Research Organization: Duke Univ., Durham, NC (United States). Dept. of Mechanical Engineering and Materials Science
• Sponsoring Organization: USDOE Assistant Secretary for Fossil Energy, Washington, DC (United States)
• DOE Contract Number: FG22-93PC93219
• OSTI ID: 475616
• Report Number(s): DOE/PC/93219--T13; ON: DE97052310
• Country of Publication: United States
• Language: English

Related Subjects

30 DIRECT ENERGY CONVERSION
36 MATERIALS SCIENCE
CARBON 12
CARBON 13
CARBON IONS
CERIUM CARBIDES
CRYSTAL STRUCTURE
DESIGN
DIFFUSION
ERBIUM CARBIDES
FABRICATION
FLUORITE
FUEL CELLS
IONIC CONDUCTIVITY
MASS SPECTROSCOPY
PROGRESS REPORT
SOLID ELECTROLYTES
SURFACE COATING
THERMODYNAMICS
X-RAY DIFFRACTION