Electrochemical performance of B and M phases VO2 nanoflowers

Abstract VO 2 exists in four phases, among which, the M/R phase VO 2 is well known for its reversible metal‐semiconductor phase transition at about 68 °C, and VO 2 (B) is a promising candidate cathode material to be applied in aqueous lithium‐ion battery owing to its proper electrode potential and layered structure. In this study, VO 2 (B) nanoflowers was synthesized via one‐step hydrothermal process and then successfully transformed into the VO 2 (M) by heat treatment. Electrochemical behaviors of the two samples were evaluated by cycling discharge and cyclic voltammetry (CV). The results showed that flower‐like VO 2 (B) had the first discharge capacity of 180.33 mAhg‐1, an outstanding value of 52.8% for the capacity retention after 50 cycles. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)