Self-templating synthesis of heteroatom-doped large-scalable carbon anodes for high-performance lithium-ion batteries

Abstract

Lithium-ion batteries (LIBs) are considered to be among the most promising electrical storage devices for large-scale applications. In order to achieve a long lifespan and high performance for LIBs, however, it is necessary to replace the traditional graphite anode with appropriate advanced anode materials. Herein, a simple and cost-effective strategy was developed to synthesize a large–scalable nitrogen-rich sulfur-doped porous carbon (NSPC) material, which when used as an anode could deliver high-rate cycle performance with a prolonged cycle life. Benefiting from the higher nitrogen content and sulfur doping, the resultant heteroatom-doped porous carbon material exhibited a significantly high initial reversible capacity of 1096 mA h g⁻¹ at a current density of 0.1 A g⁻¹ with a high initial columbic efficiency of more than 67%. Even at a significantly high current rate of 5 A g⁻¹, prolonged cycle life over 1100 cycles with outstanding cycle performance of 695 mA h g⁻¹ was achieved. The observed ultrafast lithium ion storage is attributed to the synergic effect of heteroatom-doping and abundant mesopores with a large quantity of edge defects that enable additional lithium ion storage. Density functional theory (DFT) calculations demonstrated that the introduction of N and S atoms into the porous carbon could efficiently change the charge density distributions over the carbon structure to improve the storage capacity of lithium ions and their electrochemical performance as an anode in LIBs.