Synthesis and Li⁺ Intercalation/Extraction in Ultrathin V₂O₅ Layer and Freestanding V₂O₅/Pt/PVA Multilayer Films

Abstract

A uniform V 2 O 5 nanostructured ultrathin film has been prepared by spin-coating followed by heat treatment. This V 2 O 5 nanostructured ultrathin film is composed of 4 nm closely connected V 2 O 5 domains and has lamellar structure. Compared with a thicker V 2 O 5 film (78 nm), the 17 nm V 2 O 5 film showed a very good electrochemical performance of fast charge/discharge and excellent electrochemical stability. The excellent electrochemical performance of the V 2 O 5 nanostructured ultrathin film is attributed to its nanostructure, which results in short Li + diffusion distance and free Li + accessibility to intercalation active sites. A facile approach to preparing a freestanding V 2 O 5 /Pt/PVA multilayer film on a large scale was developed. The thicknesses of the V 2 O 5, Pt, and PVA are 22, 57, and 704 nm, respectively. The freestanding multilayer is stable in air, flexible, and robust and exhibits excellent electrochemical performance.