Electrochemical intercalation of single-walled carbon nanotubes with lithium

Single-walled carbon nanotubes (SWNT) synthesized by laser ablation were electrochemically intercalated with lithium. As-grown SWNTs showed a reversible saturation composition of Li1.2C6 (450 mAh g−1). After removing the impurity phases by filtration, the reversible saturation composition increased to Li1.6C6 (600 mAh g−1), significantly higher than the ideal value of LiC6 (372 mAh g−1) for graphite. All the SWNT materials showed large irreversible capacities and voltage hysteresis. Upon processing the nanotubes by ball-milling, the reversible Li capacity increased to 1000 mAh g−1 (Li2.7C6) while the irreversible capacity decreased to 650 mAh g−1.