Carbon Nanorings and Their Enhanced Lithium Storage Properties

A method involving catalytic growth of carbon nanorings (CNRs) with an outer diameter of ∼20 nm and axial length of ∼1 nm in the confined interlayer galleries of a layered double hydroxide host co-intercalated with a carbon source and charge-balancing anion is reported. The as-prepared CNRs with open tips and a ratio of length to diameter (L/d) of much less than 1 exhibit excellent lithium storage performance, especially large reversible specific capacity under high-rate charge and discharge.