SnO2 quantum dots @ 3D sulfur-doped reduced graphene oxides as active and durable anode for lithium ion batteries

Abstract

SnO2 has attracted growing attention as a promising anode material for next generation of Lithium ion batteries because of its high theoretical capacity (1494 mAh g−1) and low working potential. However, the severe volume change during cycling remains one of the great challenges for its practical application. To overcome the obstacle, we propose to utilize the SnO2 quantum dots loaded on the sulfur-doped reduced graphene oxides by one-pot synthesis. The SnO2 quantum dots are uniformly dispersed on the sulfur-doped reduced graphene oxides and retain their tiny sizes during the electrochemical reaction, thus alleviate the volume expansion. Meanwhile, the sulfur-doped reduced graphene oxides introduces many defects and can benefit charge transfer and lithium ion diffusion in the electrode. With the synergetic effect between SnO2 quantum dots and sulfur-doped reduced graphene oxides, the composite anode material can deliver a specific capacity of 897 mA h g−1 at 100 mA g−1 and maintain 88% of original capacity after over 500 cycles at 500 mA g−1, featuring large lithium ion storage capacity and high stability.