THERMIONIC EMITTING METAL INTERCALATED GRAPHITIC NANOFIBERS

Abstract:

A carbon-based composition comprising graphite carbon nano-fibers intercalated with a metal useful as a thermionic electron emission material.

Applicants:VANDERBILT UNIVERSITY [US/US]; 1207 17th Avenue South, Suite 105, Nashville, TN 37212 (US) (All Except US).
LUKEHART, Charles, M. [US/US]; 1207 17th Avenue South, Suite 105, Nashville, TN 37212 (US) (US Only).
MICHEL, Jason, A. [US/US]; 1207 17th Avenue South, Suite 105, Nashville, TN 37212 (US) (US Only).
FISHER, Timothy [US/US]; 1207 17th Avenue South, Suite 105, Nashville, TN 37212 (US) (US Only).
ROBINSON, Vance [US/US]; 1207 17th Avenue South, Suite 105, Nashville, TN 37212 (US) (US Only).

Title:	THERMIONIC EMITTING METAL INTERCALATED GRAPHITIC NANOFIBERS
Abstract:	A carbon-based composition comprising graphite carbon nano-fibers intercalated with a metal useful as a thermionic electron emission material.

Claims:

1. A carbon-based composition comprising graphite carbon nano-fibers intercalated with a metal.

2. A composition of claim 1 wherein said metal is an alkali metal.

3. A composition of claim 2 wherein said alkali metal is potassium.

4. A thermionic electron emission material comprising the composition of claim 1.

[0017] The present invention is predicated on the discovery that certain metal intercalated GCNF materials possess unexpectedly low work functions and

concomitant enhanced thermionic emission properties. Preferred intercalating metals are the alkali metals. Particularly preferred is potassium.

[0018] More particularly, it has unexpectedly1 found that the thermionic electron energy distributions (TEEDs) from GCNFs with and without potassium intercalation reveal a dramatic reduction in work function from 4.7 eV to 2.2 eV due to the intercalation. This reduction is generally consistent with prior photoemission experiments on fibrous carbon materials with intercalated alkali metals; however an important difference is that the present results were performed at elevated temperatures. These results indicate that the effect can be maintained at the high temperatures required in applications of these materials as thermionic electron sources and energy conversion materials.

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