▎ 摘　　要

Polydopamine (PDA) functionalized graphene/NiFe2O4 (GNSs-PDA-NiFe2O4) nanocomposite has been successfully synthesized through an in-situ ultrasonic method. The obtained GNSs-PDA-NiFe2O4 nanocomposite shows a reversible capacity up to 947 mAh g(-1) and much improved rate capability, e.g. delivering a capacity of 562 mAh g(-1) at 5 A g(-1), about 7 times higher than that of graphene/NiFe2O4 nanocomposite. The improvement in the rate capability of the obtained GNSs-PDA-NiFe2O4 nanocomposite can be attributed to the improved interactions between graphene and NiFe2O4 derived from PDA, and a high conductive network fabricated by PDA functionalized graphene, which can be supported by TEM images and EIS measurements. Further studies reveal the strong graphene-NiFe2O4 interactions are also beneficial for retaining the high conductive network after the charge-discharge processes, and further beneficial for its cyclic stability. (C) 2014 Elsevier Ltd. All rights reserved.