Lamellar MoSe2 nanosheets embedded with MoO2 nanoparticles: novel hybrid nanostructures promoted excellent performances for lithium ion batteries.

A carbon-free nanocomposite consisting of MoO2 nanoparticles embedded between MoSe2 nanosheets, named MoO2@MoSe2, has been synthesized and demonstrated excellent electrochemical properties for lithium ion batteries. In such a composite, MoSe2 nanosheets provide a flexible substrate for MoO2 nanoparticles; while MoO2 nanoparticles act as spacers to retain the desired active surface to electrolyte and also introduce metallic conduction. In addition, the heterojunctions at the interface between MoSe2 and MoO2 introduce a self-built electric field to promote the lithiation/delithiation process. As a result, such lamellar composite has a long cycling stability with a reversible capacity of 520.4 mA h g-1 at a current density of 2000 mA g-1 after 400 cycles and excellent rate performance, which are attributed to the synergistic combination of the two components in nanoscale.