Enhanced electrochemical performance of MnO nanowire/graphene composite during cycling as the anode material for lithium-ion batteries

Generally, the capacity of lithium-ion batteries (LIBs) will fade gradually during cycling especially under large current densities because of the structural collapse of electrode materials. Herein, dramatic and favorable electrochemical performance enhancement was observed in a simply achieved MnO nanowire/graphene composite during long-term cycling when utilized as the anode material for LIBs. Characterized by high-resolution transmission electron microscopy, X-ray diffraction and Fourier-transfer infrared spectroscopy, the MnO nanowires were gradually collapsed to nano-spindles and further nanoparticles but these newly formed nanoparticles are still stably anchored on the graphene lamellas. Correspondingly, the specific capacity of the MnO nanowire/graphene electrode exhibited a significant enhancement with a durable life after a slight decrease in the first several cycles. The reason for the self-enhancement could be ascribed to the strong interphase interaction between MnO and graphene flakes. Our work provides a new understanding and insight for the electrochemical behavior of composite electrodes in LIBs and is helpful for the fabrication of high-performance anode materials. (C) 2014 Elsevier Ltd. All rights reserved.