Facile synthesis of MoS2/graphite intercalated composite with enhanced electrochemical performance for sodium ion battery

MoS2 is a promising anode material for sodium ion batteries owing to its two-dimensional layered structure and high specific capacity. But it still exhibits a poor cycle stability and limited rate capability for Na+ storage because of its poor electrical conductivity and structural instability. In this work, MoS2/graphite composite is fabricated by mechanically delaminated and restacked MoS2 and graphite to form two-dimensional composite layers. The graphite sheets will improve electrical conductivity and prevent the aggregation as well as structure collapse of the MoS2 layers during charge-discharge process. The MoS2/graphite composite exhibits excellent Na+ storage properties. It delivers a high discharge specific capacity of 358.2 mAh/g at a current density of 100 mA/g in the first discharge process and with capacity retention of 68.1% after 800 cycles (retains 244 mAh/g). The average discharge specific capacities retain 250.9 and 225.4 mAh/g corresponding to the current densities of 100 and 10 0 0 mA/g, showing excellent rate capability. The improved electrochemical performance is attributed to the improved electrical conductivity and structural stability after composition of graphite sheets. The study demonstrates a new research strategy for improving sodium ion storage properties of MoS2. (C) 2017 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. and Science Press. All rights reserved.