V3S4 nanoparticles anchored on three-dimensional porous graphene gel for superior lithium storage

V3S4 nanoparticles anchored on three-dimensional (3D) reduced graphene oxide gel (V3S4-rGO) is successfully fabricated as a novel anode material for lithium-ion batteries. The V3S4 nanoparticles with a size of 200–300 nm are homogeneously and tightly adhered to the surface of graphene nanosheets. The interactions between V3S4 nanoparticles and rGO are examined through density functional theory (DFT) calculations with van der Waals forces considered. The nanoscale V3S4 not only exhibits a high theoretical capacity and a high electric conductivity, but also provides a short pathway for electron transportation and Li+ diffusion. Meanwhile, the 3D porous rGO gel can provide a continuous electric conductive network and also act as buffers for volume expansion during the repeated lithiation/delithiation process. Compared with the previous reported V2O3-rGO hybrid, the resultant V3S4-rGO electrode exhibits a better electrochemical performance with a high reversible specific capacity (873 mAh g−1 after 200 cycles at 0.2 C) and a high rate capability (502 mAh g−1 at 5 C and 338.7 mAh g−1 at 10 C) owing to the high content of active V3S4 and its unique nanostructures.