Necklace-Like Structures Composed of Fe3N@C Yolk-Shell Particles as an Advanced Anode for Sodium-Ion Batteries

It is of great importance to develop cost-effective electrode materials for large-scale use of Na-ion batteries. Here, a binder-free electrode based on necklace-like structures composed of Fe3N@C yolk-shell particles as an advanced anode for Na-ion batteries is reported. In this electrode, every Fe3N@C unit has a novel yolk-shell structure, which can accommodate the volumetric changes of Fe3N during the (de)sodiation processes for superior structural integrity. Moreover, all reaction units are threaded along the carbon fibers, guaranteeing excellent kinetics for the electrochemical reactions. As a result, when evaluated as an anode material for Na-ion batteries, the Fe3N@C nano-necklace electrode delivers a prolonged cycle life over 300 cycles, and achieves a high C-rate capacity of 248 mAh g(-1) at 2 A g(-1).