A unique hierarchical composite with auricular-like MoS2 nanosheets erected on graphene for enhanced lithium storage

Abstract

Molybdenum disulfide (MoS2) is a promising anode material in lithium-ion batteries (LIBs) due to its high specific capacity and typical two-dimensional layered structure. In this work, the MoS2-graphene composite with unique hierarchical structure was successfully prepared by ethanolamine-assisted hydrothermal method. Raman spectroscopy showed that MoS2 in the composite was a single or double layer. And the ID/IG value (1.13) of the composite indicated that it had some defects and disordered structure. X-ray photoelectron spectra illustrated that the majority of Mo and S elements existed in the composite in the form of Mo4+ and S2−, and the Mo to S atomic ratio was 1:1.89. Scanning electron microscopy images showed that the majority of auricular-like MoS2 nanosheets uniformly distributed upright on the graphene surface. Serving as anode material for LIBs, the composite exhibited a high reversible specific capacity, 1133 mAh g−1 (90.4% of the initial capacity) at 200 mA g−1 after 150 cycles. In addition, a specific capacity of 774 mAh g−1 was still achieved even at a high current density of 1000 mA g−1 after 600 cycles. The excellent electrochemical property of the composite was attributed to the combined action of unique hierarchical architecture, unstacked MoS2 nanosheets, and highly conductive graphene. This work may offer a rational strategy for synthesizing transition mental sulfide-graphene composite with two-dimensional hierarchical structure as high-performance LIBs anodes.