Facile Synthesis of Nitrogen-Doped Double-Shelled\nHollow Mesoporous Carbon Nanospheres as High-Performance Anode Materials\nfor Lithium Ion Batteries

Abstract

In\nthis work, a facile “soft-template” route to synthesize\nnitrogen-doped double-shelled hollow mesoporous carbon spheres (N-DHMCSs)\nhas been developed by using anionic block copolymer polystyrene-<i>b</i>-poly­(acrylic acid) (PS-<i>b</i>-PAA) micelles\nas soft template, tetraethyl orthosilicate (TEOS) as silica source,\nand dopamine (DA) as carbon and nitrogen sources, respectively. After\ncarbonization of the PDA precursors and the removal of silica, the\nobtained N-DHMCSs present high specific surface area (>600 m²/g), adjustable nitrogen doping content (4.02%–5.91%\nin weight\nratios), and unique double-shell hollow structures. Especially, the\nsample of N-DHMCSs-800 carbonized at 800 °C exhibits a high discharge\nspecific capacity of 920.3 mA h/g at a current density of 0.1 A/g\nafter 100 cycles. In addition, at a relative high current density\nof 0.5 A/g, its discharge specific capacity is up to 614.1 mA h/g\neven after 300 cycles. More importantly, it demonstrates excellent\nrate capabilities by the fact that a high reversible capacity of 910.9\nmA h/g was maintained after cycling at different current densities.\nTherefore, it is anticipated that such a facile “soft-template”\nstrategy can provide us a promising platform for preparing multishelled\nand hollow structured nanomaterials with various components and functions.