▎ 摘　　要

SnO2 is considered as one of the anode material for Li-ion batteries in terms of its superiority in high theoretical capacity (1494 mAh g(-1)), low cost and environmental friendly. However, it is suffered from several issues such as rapid capacity deterioration, undesirable aggregation of tin particles and pesky expansion of volume. To conquer these shortcomings, a novel composite of ultrasmall SnO2 quantum dots with an average particle size of 4-5 nm anchored on nitrogen-doped reduced graphene oxide (SnO2@NRGO) was first in situ synthesized By means of hydrothermal method. The results show that as-prepared SnO2@NRGO electrode exhibits a greater enhancement in its initial discharge capacity (1678.4 mAh g(-1)) and reversible capacity (1333.5 mAh g(-1) after 450 cycles) at a current density of 500 mA g(-1), implying a long cycle life. Furthermore, the high rate capability of SnO2@NRGO is superior to SnO2@RGO and SnO2 electrodes. The excellent electrochemical reversibility of SnO2@NRGO electrode can be ascribed to the great conductivity, ultrahigh specific surface area and the synergetic effect between ultrasmall SnO2 quantum dots and NRGO. (C) 2017 Elsevier B.V. All rights reserved.