One novel and universal method to prepare transition metal nitrides doped graphene anodes for Li-ion battery

Abstract

Transition metal nitrides (TMN)/N modified graphene (N-rG-O) composites are prepared by annealing of Metaln+-EN (EN: ethylene diamine) chelate and G-O composite. Li-storage and cycling behavior of TMN/N-rG-O composite have been evaluated by galvanostatic discharge-charge and cyclic voltammetry in coin cells with Li-metal as counter electrode. FeN/N-rG-O, CoN/N-rG-O, FeCoN/N-rG-O, NiN/N-rG-O are prepared using this method, and all have shown pronounced cyclability and considerable high capacity value. Even a low loading of TMN (12.5% ±2.0%) on graphene can significantly improve the Li-ion storage capacity of graphene. For example, FeN/N-rG-O with FeN weight ratio of only 12.5% has an initial reversible capacity of 665±10 mAhg−1 at a current density of 50mAg−1, and the capacity value further increase consistently to 698 ±10 mAhg−1 after 50 cycles. The excellent cyclability, low charge/discharge potentials (<1.5V), high reversible capacity values of TMN/N-RG-O indicate they are prospective anodes for Li-ion batteries.