Facile synthesis of core/shell-structured Sn/onion-like carbon nanocapsules as high-performance anode material for lithium-ion batteries

Core/shell-structured Sn/C nanocapsules with Sn nanoparticles as the core and defective onion-like carbon as the shell are synthesized by a modified arc-discharge method. The Sn/C nanocapsule anode maintains a high discharge capacity of 585 mAh g−1 after 100 cycles at 0.1 A g−1 and obtains a high reversible capacity of~480 mAh g−1 at 5 A g−1. The remarkable electrochemical performance is attributed to the effective combination of the Sn nanoparticle cores and the defective onion-like carbon shells, which simultaneously solves the major problems of pulverization, loss of electrical contact, and particle aggregation encountered in Sn anode.