Three-dimensional MoO2@few-layered MoS2 covered by S-doped graphene aerogel for enhanced lithium ion storage

MoO2 with low electrical resistivity and high specific capacity as anode for lithium ion batteries is hindered because of its large volume variation during Li+ insertion/extraction process, which leads to fast capacity fading. Herein, three-dimensional (3D) core-shell MoO2@few-layered MoS2 covered by S-doped graphene (MO/MS/SG) aerogel has been fabricated through hydrothermal reaction and freeze-drying process together with sulfidation. MoO2 nanoparticles coated by few-layer MoS2 can promote good dispersion of MoO2 nanoparticles and avoid the restacking of MoS2. S doping in graphene can increase the defects and active sites. S-doped graphene aerogel as flexible framework and conductive network not only provides the transmission path for ions and electrons, but also maintains the structural integrity of electrode during cycles. Core-shell MoO2@few-layer MoS2 hybrid well-dispersed in S-doped graphene matrix buffers the volume changes during cycles and contributes to high reversible capacity. Free-standing electrode without binder and current collector prevents the separation of electrode materials from current collector during cycles. Benefitting from the unique structures, the MO/MS/SG aerogel as anode for lithium ion battery exhibits high reversible capacities of 683 mAh g(-1) at 0.1 Ag-1 after 100 cycles and 533 mAh g(-1) at 0.5 Ag-1 after 350 cycles together with excellent rate capability. This work demonstrates the potential application of the Mo-based materials in lithium ion batteries. (C) 2018 Elsevier Ltd. All rights reserved.