Facile synthesis of nitrogen-doped Sn@NC composites as high-performance anodes for lithium-ion batteries

Owing to its high capacity of 994 mAh g −1 , low cost, and environmental friendliness , tin (Sn) is considered as an advanced anode material for high-capacity lithium-ion batteries (LIBs). Here, a facile strategy to fabricate core-shell structured Sn@NC composites with one-step and large-scale production is introduced in a liquid-phase reaction under room temperature . When used as anode materials for LIBs, the optimal Sn@NC composite delivers a high reversible discharge capacity of 761.2 and 476 mAh g −1 at a current density of 200 and 1000 mA g −1 after 200 cycles, respectively. A high capacity of 328.3 mAh g −1 can also be obtained even at a current density of 2000 mA g −1 . The excellent cycling stability and rate performance of the composite can be ascribed to the synergistic effect of the nanometer size of Sn powder and porous structure of the carbon shell, both of which can effectively reduce the absolute volume change of electrode during the repeated charge-discharge cycles, and thus lead to excellent electrochemical performances at both rate capability and cycling life.