Lonicerae flos-derived N, S co-doped graphitized carbon uniformly embedded with FeS2 nanoparticles as anode materials for high performance lithium ion batteries

Metal sulfides still face significant challenges in terms of large volume expansion and poor conductivity as anodes for lithium ion batteries. For the past few years, many researches have shown that the preparation of the composite of metal sulfide and heteroatom doped graphitized carbon with high conductivity has become an effective method to improve its lithium storage performance. In this work, FeS2 @N/S-C composite was successfully synthesized through homogeneously embedding FeS2 nanoparticles into N and S co-doped biomass-derived graphitized carbon, by using Lonicerae flos as carbon source and bio-template. It is worth noting that the introduction of Fe ions effectively enhances the graphitization degree of the N, S co-doped carbon material derived from Lonicerae flos, thus improves the conductivity and stability of the composite. At the same time, the uniform coating of highly conductive carbon effectively inhibits the growth and agglomeration of FeS2 nanoparticles during the process of charge and discharge. Therefore, the FeS2 @N/S-C electrode exhibits large lithium storage capacity, delivers a high capacity of 1259 mA h g−1 at 0.1 A g−1 after 100 cycles, and excellent long-term cycle performance at 1.0 A g−1 (528 mA h g−1 after 1000 cycles). These results indicate that the as-prepared FeS2 @N/S-C composite is a promising anode.