One-pot high temperature hydrothermal synthesis of Fe3O4@C/graphene nanocomposite as anode for high rate lithium ion battery

This study develops a facile and effective methodology to synthesize carbon-coated Fe3O4/graphene composite in one-pot high temperature hydrothermal processing, which not only simplifies the synthesis procedure, but also partly avoids graphene re-stacking and aggregation of Fe3O4 nanoparticles. Fe3O4@C nanoparticles of about 50 nm are uniformly dispersed on the graphene nanosheets. The electrochemical test of the Fe3O4@C/g-raphene nanocomposite demonstrates high rate capacity. The first reversible specific capacity is 1016.6 mAhg(-1) and increases to 1199.8 mAhg(-1) after 500 cycles at 1.0 A g(-1), and the reversible specific capacity at 20.0 A g(-1) remains 52.8% of that at 0.2 A g(-1). The excellent electrochemical performance can be attributed to high extrinsic conductivity where carbon layer and graphene can provide rapid transfer channels for electrons and small particles size that can accommodate volumetric changes of Fe3O4 due to their elastic feature. In addition, the winkle structure representing a curled and corrugated morphology that the graphene owns intrinsically may also act as lithium ion rapid transfer channels. Full batteries using the Fe3O4@C/graphene nanocomposite as the anode and lithium nickel cobalt manganese oxide as the cathode show excellent cycle performance. (C) 2015 Elsevier Ltd. All rights reserved.