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

摘要

Graphitic carbon nitride (g-C_3N_4) 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-C_3N_4 due to its high nitrogen content. Urea, dicyandiamide or melamine can be used as organic precursor to form g-C_3N_4 because they can be pyrolyzed into g-C_3N_4 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-C_3N_4 organic precursor and SnCl_2 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.