Preparation of different FexN/rGO nanocomposites and their application as anodes for lithium-ion battery

Iron-nitride based materials are considered to be one of the most promising anode materials for Lithium-ion batteries (LIBs) due to their good electrical conductivity and high theoretical capacity. However, iron-based nitrides are easily deteriorated in the long-term lithiation/delithiation process, which reduces the electrochemical stability and limits their large-scale application. Here, we report a Fe 3 N or Fe 2 N reduced graphene oxide nanosheets (rGO) composite prepared through a facile annealing process under different atmosphere (NH 3 /Ar) from Fe 3 O 4 original material. The voids in cubic structure of Fe 3 N or Fe 2 N can be beneficial to buffer volume changes during lithiation/delithiation processes and provide active sites, and the rGO is helpful to improve electrical conductivity of composites. Moreover, the proportion of Fe 3 N in the composite is higher than that of Fe 2 N, indicating that more cubic structure can be released in Fe 3 N/rGO. Therefore, Fe 3 N/rGO showed a higher capacity (513 mA h g −1 after 200 cycles at a current density of 0.5 A g −1 ), better rate performance and more stable cycling performance. This work provides a new direction for the construction of iron-based nitrides with different valence states as anode active materials for LIBs using Fe 3 O 4 as raw material.