▎ 摘　　要

Zinc oxide (ZnO) nanocrystals attached to graphene nanosheets (GNs) have been fabricated by an efficient method, consisted of (i) microwave heating, (ii) modified Hummers' method, and (iii) homogenizing dispersion. Highly-crystalline ZnO nanocrystals, having a size of 80-100nm, are uniformly dispersed over the both sides of GNs and inserted into the interspacing layers, forming ZnO@GN framework. The ZnO@GN hybrids serve as anode material for the investigation of Li+ insertion/extraction at different rates. The as-prepared ZnO@GN anodes exhibit improved performance in terms of Li-storage capacity (850 mAh g(-1) at 0.1 C), high Coulombic efficiency (82.1% at 1st cycle), excellent rate capability (capacity retention similar to 60% at 5 C), and good cycling stability (capacity decay similar to 8% after 50 cycles), as compared with the fresh GN anode. The enhancement of performance can be attributed to the fact that well-dispersed ZnO nanocrystals serve as not only spacer to support the stereo GN framework but also redox site for enhancement of Li-storage capacity and ionic diffusion rate. (C) 2013 Elsevier Ltd. All rights reserved.