Self-templated formation of tremella-like MoS2 with expanded spacing of (002) crystal planes for Li-ion batteries

Tremella-like MoS2 consisting of ultrathin nanosheets (similar to 7 nm in thickness) is prepared via a one-pot hydrothermal reaction without using any surfactants and templates. The reaction involves transforming precursor MoO3 to polyhedral intermediate (K2NaMoO3F3 and K-3 Mo2O4F5) through its reaction with Na+, K+, and F- ions in the initial stage of hydrothermal reaction. Then the polyhedral intermediate acting as the sacrifice template reacts with the S-2- released from a hydrolysis process of SCN- ion and transforms to tremella-like MoS2. The obtained MoS2 product exhibits expended spacing of the (002) crystal plane, which can facilitate faster lithium ions intercalation behavior. This tremella-like MoS2 used as an anode material for lithium-ion batteries shows a very high reversible capacity of 693 mA h g(-1) after 50 cycles, good rate capability, and high cyclic capacity retention. Even cycled at a high current density of 4800 mA g(-1), the tremella-like MoS2 still can deliver a high capacity of 252 mA h g(-1). The secondary hierarchical microstructures consisting of ultrathin nanosheets are beneficial to greatly improved electrochemical performance of the MoS2 electrode.