Facile self-templating synthesis of layered carbon with N, S dual doping for highly efficient sodium storage

Nitrogen and sulfur co-doping is emerging as a promising approach to prominently improve the sodium storage performance of carbonaceous materials. However, poisonous chemicals and rigorous conditions are normally involved in their preparation, especially in the sulfidation process. Therefore, developing novel, facile and eco-friendly approaches to construct nitrogen and sulfur co-doped carbon (NSC) is still challenging. In this work, a facile self-templating synthesis method is reported to allow the simple and green preparation of NSC. Particularly, small-molecule dithiooxamide can be directly converted to NSC through a facile thermal condensation process, serving as precursor, template, and self-doping agent simultaneously. In account of its high ionic and electronic conductivity, increased interlayer spacing, unique layers assembled structure and efficient N, S co-doping, the NSC obtained at 800 °C exhibits excellent sodium storage performances, including prominent reversible capacity (316.1 mAh g⁻¹ at 0.1 A g⁻¹ up to 100 cycles), remarkable rate capability (178.3 mAh g⁻¹ at 3 A g⁻¹), and robust stability upon long-term cycling (213.6 mAh g⁻¹ at 1 A g⁻¹ up to 2000 cycles), rendering itself to be a promising candidate for practical sodium-ion battery.