Bottom-up synthesis of nitrogen-doped graphene sheets for ultrafast lithium storage

Abstract

A facile bottom-up strategy was developed to fabricate nitrogen-doped graphene sheets (NGSs) from glucose using a sacrificial template synthesis method. Three main types of nitrogen dopants (pyridinic, pyrrolic and graphitic nitrogens) were introduced into the graphene lattice, and an inimitable microporous structure of NGS with a high specific surface area of 504 m² g⁻¹ was obtained. Particularly, with hybrid features of lithium ion batteries and Faradic capacitors at a low rate and features of Faradic capacitors at a high rate, the NGS presents a superior lithium storage performance. During electrochemical cycling, the NGS electrode afforded an enhanced reversible capacity of 832.4 mA h g⁻¹ at 100 mA g⁻¹ and an excellent cycling stability of 750.7 mA h g⁻¹ after 108 discharge–charge cycles. Furthermore, an astonishing rate capability of 333 mA h g⁻¹ at 10 000 mA g⁻¹ and a high rate cycle performance of 280.6 mA h g⁻¹ even after 1200 cycles were also achieved, highlighting the significance of nitrogen doping on the maximum utilization of graphene-based materials for advanced lithium storage.