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 (~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 K3Mo2O4F5) 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 S2− 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.