Metal–Organic Frameworks Mediated Synthesis of One-Dimensional Molybdenum-Based/Carbon Composites for Enhanced Lithium Storage

Abstract

Molybdenum (Mo)-based compounds with properly engineered nanostructures usually possess improved reversible lithium storage capabilities, which offer great promise to boost the performance of lithium-ion batteries (LIBs). Nevertheless, a lack of efficient and high-yield methods for constructing rational nanostructures has largely restricted the application of these potentially important materials. Herein we demonstrate a metal-organic frameworks (MOFs) mediated strategy to successfully synthesize a series of one-dimensional Mo-based/carbon composites with distinct nanostructures. In this process, starting from well-designed MoO₃ nanorods, the crystal control growth is first proposed that a layer of MOFs is achieved to be controllably grown on surfaces of MoO₃, forming an obvious core-shell structure, and then the adopted precursor can be in situ transformed into MoO₂ or Mo₂C which are both well confined in conductive porous carbons through direct carbonization at different temperatures, where the MOFs shell serve as both carbon sources and the reactant to react with MoO₃ simultaneously. Benefiting from this design, all optimized products exhibit enhanced electrochemical performances when evaluated as anode materials for LIBs, especially the hollow MoO₂/C and core-shell Mo₂C/C electrodes, show best reversible capacities up to 810 and 530 mAh g^-1 even after 600 cycles at a current density of 1 A g^-1, respectively. So this work may broaden the application of MOFs as a kind of coating materials and elucidates the attractive lithium storage performances of molybdenum-based compounds.