Synthesis of NaV6O15 nanorods via thermal oxidation of sodium-intercalated 2D V2CTx and their electrochemical properties as anode for lithium-ion batteries

Herein, a ternary vanadium bronze compound, NaV6O15 was synthesized via a low temperature thermal oxidization of sodium-intercalated V2CTx, which exhibited a higher specific capacity than the precursor V2CTx when used as the anode material for lithium-ion batteries (LIBs). The characterization results showed that the NaV6O15 nanorods spontaneously grew in the interlayers and directly damaged the layered structure of MXene. Moreover, the charge-discharge result demonstrated an initial specific discharge capacity of 350 mAh g−1 under a current density of 50 mA g−1 was achieved and, in particular, a specific capacity of 120 mAh g−1 and a Coulombic efficiency of 100% were maintained after as many as 200 cycles at 1000 mA g−1 without the lattice expansion and deformation of NaV6O15 during the lithium-ion insertion/de-insertion process. According to these results, it is therefore expected that optimizing the process further to oxidize other metal cations intercalated-MXene will exploit other nanostructures employed as the electrode in LIBs and demonstrate immeasurable performance.