Vanadium oxide nanodisks: Synthesis, characterization, and electrochemical properties

Highlights: ► Highly crystallined VO1.6·H2O nanodisks have been synthesized by using a novel solid–solution–solid growth process. ► The nanodisks are assembled from nanoparticles. ► PEG-4000 plays an important role for the formation of the nanodisks. ► The as-synthesized nanodisks exhibit good electrochemical behavior. -- Abstract: Highly crystallined VO1.6·H2O nanodisks assembled from nanoparticles have been successfully fabricated under hydrothermal conditions by using bulk V2O5 and Na2S2O3 as the starting materials in the presence of surfactant polyethylene glycol 4000 (PEG-4000). The nanodisks have a diameter of 200 nm and thickness of 40 nm. Hollow nanodisks are occasionally observed, which is similar to Chinese ancient copper coins. The formation of nanodisks can be ascribed to a novel solid-solution-solid growth mechanism. Compared with other methods, the solid state transformation method is simple and economic. In addition, the nanodisks exhibit good electrochemical behavior and promising to be used in lithium-ion battery.