Ultrahigh nitrogen-doped carbon/superfine-Sn particles for lithium ion battery anode

Graphitic carbon nitride (g-C₃N₄) can be indexed as a high-content N-doped carbon material, appealing great attentions in energy storage devices. However, poor conductivity and serious irreversible capacity loss were found for the g-C₃N₄ due to its high nitrogen content. Urea, dicyandiamide or melamine can be used as organic precursor to form g-C₃N₄ because they can be pyrolyzed into g-C₃N₄ easily. In this work, high nitrogen content (up to 17 at.%)-doped carbon materials embedded with superfine-Sn particle are synthesized by one-step thermal treatment of the g-C₃N₄ organic precursor and SnCl₂ in a simple self-designed quartz tube. Regarding their high nitrogen doping content, large surface area and porous structure, the obtained material could deliver a high specific capacity and excellent capacity retention when applied as lithium ion battery anode. Its excellent rate performance is attributed to the high Li diffusion coefficient demonstrated by the GITT kinetics analysis. This extremely simple and low-cost preparation process could provide a new strategy to obtain high nitrogen content carbon-based materials.