Facile synthesis and electrochemical properties of nanoflake VN for supercapacitors

Abstract

Vanadium nitrides (VN) have drawn much attention due to their large negative potential window, high electronic conductivity and fast reversible redox reaction. The electrochemical performances of VN are affected by their morphology and specific surface area, which depend deeply on the synthesis method. Herein, a large-sized nanoflake V₂O₅ xerogel is synthesized by a hydrothermal method followed by freeze drying, and then the nanoflake V₂O₅ xerogel is thermally treated for various times under NH₃ atmosphere to study the nitriding process. The results show that the nanoflake V₂O₅ xerogel is reduced to nanoflake V₂O₃ before being completely transformed into nanoflake VN. The nanoflake VN demonstrate superior capacitive performance than the nanoflake V₂O₅ xerogel and intermediate V₂O₃, which arises from higher intrinsic conductivity.