Nanostructured ZnSe Anchored on Graphene Nanosheets with Superior Electrochemical Properties for Lithium ion Batteries

A facile route for the synthesis of ZnSe-reduced graphene oxide (rGO) nanocomposites is reported. The ZnSe nanoparticles with irregular shapes are similar to 40 nm in size and anchored on graphene nanosheets. As the electrode material for lithium ion batteries (LIBs), the ZnSe-rGO nanocomposites exhibit better electrochemical performances than the bare ZnSe. The nanocomposites demonstrate high reversible capacity of 876 mA h g(-1) at 100 mA g(-1) after 50 cycles, outstanding cyclic performance and excellent rate capability (778 mA h g(-1) even after 400 cycles at 1000 mA g(-1) with nearly 100% coulombic efficiency). The improvement in Li-storage properties of ZnSe-rGO is attributed to the synergetic effects between ZnSe nanoparticles and graphene nanosheets. The unique structure restrains the aggregation of ZnSe nanoparticles and graphene nanosheets to some extent, improves the conductivity of nanocomposites, buffers the volume changes of ZnSe nanoparticles during the conversion reactions, and provides more exposed available surfaces for Li-storage. The excellent electrochemical properties reveal ZnSe-rGO nanocomposite is a promising candidate as electrode materials for LIBs applications. (C) 2015 Elsevier Ltd. All rights reserved.