Effects of the chemical etching of single-walled carbon nanotubes on their lithium storage properties

▶ The SWCNTs are effectively purified by acidic treatment and gas-phase oxidation. ▶ The etched SWCNTs have excellent Li storage properties. ▶ The etched SWCNTs have the opened ends and the shortened length. ▶ The etched SWCNTs have various surface functional groups. ▶ The etched SWCNTs are consistent with a nongraphitic-carbon-insertion mechanism.