Carbon nanotube and process for producing the carbon nanotube, and lithium ion secondary battery using the carbon nanotube

摘要

The present invention relates to carbon nanotubes that are excellent in dispersibility and a process for producing the carbon nanotubes. The carbon nanotubes according to the present invention each comprise a wall that comprises a parallel portion and a narrowed portion having a tube outer diameter that is not more than 90% of a tube outer diameter of the parallel portion. Thus, the carbon nanotubes are readily dispersible owing to a high abundance ratio of easily-breaking portions.