A carbon-based material containing an allotrope of carbon, such as
single-walled carbon nanotubes, is capable of accepting and intercalated
alkali metal. The material exhibits a reversible capacity ranging from
approximately 650 mAh/g-1,000 mAh/g. The high capacity of the material
makes it attractive for a number of applications, such as a battery
electrode material. A method of producing a single-walled carbon nanotube
material includes purifying an as-recovered nanotube material, and
depositing the purified material onto a conductive substrate. The coated
substrate is incorporated into an electrochemical cell, an its ability to
accept intercalated materials, such as an alkali metal (e.g.--lithium) is
measured.