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In this paper, an effective strategy to fabricate mesoporous MoS 2(1-x) Se 2x composites supported on graphene sheets (meso-MoS 2(1-x) Se 2x /rGO) for use as anode materials for lithium ion batteries (LIBs) is reported. The meso-MoS 2(1-x) Se 2x /rGO composites possess a two-dimensional (2D) layered structure with well-defined mesoporosity and the MoS 2(1-x) Se 2x nanoparticles are perpendicularly grown on graphene sheets. Due to the merits of 2D layered structural configuration and sulfur-selenium coupled effect, the meso-MoS 2(1-x) Se 2x /rGO composites promise the enhanced electrochemical performance for LIBs. Introduction of Se may widen the spacing of the (002) crystal plane, as a result, rendering them more effective diffusion path for both Li + and e − during the charge and discharge process. More importantly, Se incorporation may further induce the transition of meso-MoS 2(1-x) Se 2x from 2H phase to more metallic 1 T phase. As such, the meso-MoS 1.12 Se 0.88 /rGO electrodes exhibit efficient rate capability and good cycling stability with an optimum capacity of 830 mA h g −1 at a current density of 100 mA g −1 for 150 th cycle. The meso-MoS 1.12 Se 0.88 /rGO electrode still keeps a capacity of 415.3 mA h g −1 even when the current density is 1000 mA g −1 making them promising for potential practical application. The novel synthetic strategy may be applicable to fabricate a large variety of 2D layered chalcogenide electrode materials for LIBs. [ABSTRACT FROM AUTHOR]

Abstract: In this paper, graphene-modified Li3V2(PO4)3 composites have been developed as Li-ion battery cathode materials with high specific capacity and excellent cycling stability. The composites are prepared by spray–drying process using graphene oxide nanosheet and citric acid as carbon source. X-ray diffraction patterns demonstrate that the as-prepared samples are well crystallized with orderly monoclinic structures. SEM and TEM images reveal that the 3D network graphene and Li3V2(PO4)3 primary nanoparticles interlace with each other. The citric acid-derived amorphous carbon species interrupt the stacking of graphene sheets and minimize in-plane anisotropy of electronic migration within graphene layers, which would facilitate fast electron migration and Li+ diffusion throughout the micro-sized spherical secondary particles. The discharge capacity of the composite could respectively achieve 131.4 and 181.5mAhg−1 in the voltage range 3.0–4.3V and 3.0–4.8V at 0.1C discharge rate, which almost reach the theoretical capacity of the cathode material. Both of them nearly showed no capacity decay at 0.1C charging and discharging rate after long cycles. [Copyright &y& Elsevier]