Uniform small-sized MoS2 from novel solution-based microwave-assisted method with exceptional reversible lithium storage properties

Nanoscale. 2018 Aug 16;10(32):15222-15228. doi: 10.1039/c8nr02833h.

Abstract

Currently, MoS2 is being investigated as a lithium-ion battery (LIB) anode material because of its high theoretical capacity. However, its significantly low electrochemical activity and cyclic stability limit its utilization. Nevertheless, small-sized MoS2 possibly overcomes these issues. Herein, small-sized MoS2 with uniform particle sizes of about 20-30 nm was prepared via a novel solution-based microwave-assisted precursor pyrolysis method. The resultant MW-MoS2 sample has a high surface area of 96.9 m2 g-1 and large pore volume (0.38 cm3 g-1) with pore size distribution mainly in the meso/macropore scale, which are beneficial for electrolyte storage and low charge carrier conductive resistances. The large pore surface area and volume of the small-sized MoS2 can also ease the volume expansion during the charging and discharging process. As an LIB anode, the MW-MoS2 material exhibits an amazingly large specific capacity of 1355 mA h g-1 at a low current density of 0.5 A g-1. At a high current density of 10 A g-1, a specific capacity of 435 mA h g-1 is obtained, demonstrating its excellent rate capability. Furthermore, a large discharge capacity of 544 mA h g-1 is maintained after 500 cycles at 5 A g-1, indicating its fascinatingly high cyclic stability.