Electrochemical and Pseudocapacitive Analysis of Rod-Like MoO_(2)@MoSe_(2)@NC Heterostructures for High-Performance Lithium Ion Batteries

摘要

A micro-scale rod-like heterostructure derived from molybdenum-based metal organic framework(Mo-MOF)has been successfully prepared via subsequent annealing treatment,which assembled from N-doped carbon encapsulated MoSe_(2) nanosheets grown on the surface of MoO_(2) microrod(named as MoO_(2)@MoSe_(2)@NC).For this novel heterostructure,the MoO_(2) nanoparticles assembled into rod core not only serve as supporting substrate for facilitating the fast kinetics of Li+cations inside the electrode but also protect the MoSe_(2) structure from restacking in the charge/discharge process.Moreover,the outer-layered MoSe2 nanosheets enable the fast lithium ion movement owing to its large interlayer spacing.Moreover,this unique rod-like core-shell structure composite could further effectively alleviate the structural strains caused by large volume expansion during charge/discharge process,thus leading to stable electrochemical performance when evaluated as anode material for lithium ion batteries.Electrochemical testing exhibits that the MoO_(2)@MoSe_(2)@NC heterostructure presents highly reversible capacity of 468 mAh g^(-1)at 0.5 A g^(-1)and superior rate capability(318 mAh g^(-1)even at 5.0 A g^(-1)),which is attributed to the synergistic effect of N-doped carbon encapsulated MoSe2 nanosheets and MoO_(2) nanoparticles.