Production of Nanoparticles of MoSe2 and Carbon in One Step to Increase Their Stability for Applications in Sodium-Ion Batteries

To meet the ever-increasing demands of sustainable energy storage devices, exploration of high-performance anode materials for sodium-ion batteries (SIBs) remains an urgent task. Currently, the preparation of MoSe2/carbon nanocompsites, one promising category of anode materials for SIBs, is always based on the stepwise generation of MoSe2 and carbon, which complicates the synthesis procedure and also faces the probability that MoSe2 may detach from carbon during repeated sodiation/desodiation reactions. This work presents a metal-organic framework (MOF)-derived strategy to synthesize embedding-type and chemically bonded MoSe2/nitrogen-doped carbon (NC) nanocomposites via the simultaneous formation of MoSe2 and carbon in one step. Two series of nanocomposites, binary MoSe2/NC and ternary MoSe2/ MoO2/NC, are obtained by adjusting the pyrolysis atmospheres and temperatures of MOFs. The microstrip-like MoSe2/NC nanocomposites obtained at a temperature of 400 degrees C exhibit the optimal Na+-storage capacity at various discharge/charge rates, the reasons for which are illustrated from the aspects of hierarchical microstrip-like morphology, ultrasmall crystallite size and expanded interlayer spacing of MoSe2, porous structure, high carbon content, and the strong chemical bonding interactions between MoSe2 and NC.