Novel bi-cation intercalated vanadium bronze nano-structures for stable and high capacity cathode materials

A new type of 3-D flower-like monoclinic sodium ammonium vanadium bronze ((NH4)0.26Na0.14V2O5)((NH4)0.26Na0.14V2O5) nano-architecture consisting of single crystalline nano-platelets was prepared. Under the hydrothermal condition, the intercalation of two kinds of cations (such as Na+ and NH4+) induced structural transformations of the vanadium bronzes and gave rise to novel crystalline structures with specific morphologies. When used as positive electrode materials in rechargeable lithium battery, this sodium ammonium vanadium bronze exhibited high discharge capacity of ca. 200 mA h g−1 in the range of 2–3.4 V and excellent cycle stability.