Controllable synthesis of nitrogen-containing core-shell carbon spheres with a gap for enhanced lithium-ions storage

Abstract

Carbon nanospheres from phenolic resin are considered as one of the most hopeful carbon-based materials for lithium storage due to the controllable size, adjustable structure, and easy fabrications. However, the lithium-ion storage properties of as-prepared carbon spheres were suppressed by the inaccessible interior sites and low heteroatom content. Here, 3-Aminophenol-Formaldehyde resin@Polystyrene@ Polypyrrole core/interlayer/shell nanospheres were designed as precursors to prepare nitrogen-containing carbon spheres. With the appropriate amount of polystyrene interlayer, carbon spheres with a gap were formed, which shown an enhanced reversible discharge capacity of 536.9 mAh g−1 after 1600 cycles at 2 A g−1. The superior electrochemical performance can be mainly ascribed to the introduction a gap between core and shell, which have made interior sites accessible. High nitrogen content and elegant nanostructure are also the main factors to improve Lithium-ions storage performance.