Bimetal phosphide Ni1.4Co0.6P nanoparticle/carbon@ nitrogen-doped graphene network as high-performance anode materials for lithium-ion batteries

Abstract Transition metal phosphides (TMPs) have attracted much considerable interest for electrochemical energy storage, due to their high theoretical capacity and earth-abundant. In this work, we report ultrafine carbon-coated bimetal phosphide nanoparticles embedded into the nitrogen-doped graphene network (NGN) through a solution-phase self-assembly strategy. The unique carbon-coated Ni1.4Co0.6P nanoparticles and strongly coupled with NGN can not only provide more active sites for lithium-ions reaction and enhance the conductivity of electrode, but also restrain the volume expansion during the charge/discharge process. When evaluated as anode material for lithium-ion batteries, the as-prepared hybrid electrode exhibits high specific capacities (1320 mAh g−1 at 120 mA g−1), superior rate capability (227 mAh g−1 at a current density of 3000 mA g−1) and excellent cycling stability (350 mAh g−1 at 1200 mA g−1 after 1000 cycles). This work can be extended to develop advanced electrode materials for next-generation energy storage systems.