Lithium insertion into chemically etched multi-walled carbon nanotubes

Lithium insertion (deinsertion) into (from) chemically etched multi-walled carbon nanotubes (c-MWNTs) has been investigated using various electrochemical techniques such as chronopotentiometry, chronoamperometry, and electrochemical impedance spectroscopy. The results indicate that not only the reversible capacity but also the rate capability was improved by a chemical etching (shortening) of the nanotubes. The observed enhancement in capability at high-rate lithium insertion/deinsertion is attributed to the increased electrochemically active area and reduced lithium diffusion length along the nanotubes, resulting from the structural defects and open ends of the c-MWNTs.