A precursor for carbon fiber production comprises a continuous lignin fiber including carbon nanotubes dispersed therein at a concentration of about 10 wt. % or less. A method of melt-spinning a continuous lignin fiber includes preparing a melt comprising molten lignin and a plurality of carbon nanotubes, and extruding the melt through a spinneret to form a continuous lignin fiber having the carbon nanotubes dispersed therein.
FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
 Pursuant to contract no. DE-AC05-000R22725 between the United States Department of Energy and UT-Battelle, LLC, the United States Government may have certain rights in this invention.