Lithiation Kinetics in High-Performance Porous Vanadium Nitride Nanosheet Anode

Vanadium nitride (VN) is promising in lithium ion battery (LIB) anode due to its high energy density, chemical stability, and corrosion resistivity. Herein, porous VN nanosheets are synthesized hydrothermally followed by an ammonia treatment. The porous nanosheets offer a large interfacial area between the electrode and electrolyte as well as short Li⁺ diffusion path and consequently, the VN nanosheets electrode has high capacity and rate capability as an anode in LIB. The VN anode delivers a high reversible capacity of 455 mAh g⁻¹ at a current density of 100 mA g⁻¹ and it remains at 341 mAh g⁻¹ when the current density is increased to 1 A g⁻¹. The charge transfer and Li⁺ diffusion kinetics during the lithiation process is studied systematically. A highly stable SEI film is formed during the initial discharging-charging cycles to achieve a long cycle life and sustained capacity at a high level for 250 discharging-charging cycles without deterioration. This work demonstrates the preparation of high-performance LIB anode materials by a simple method and elucidates the lithiation kinetics.