Nanostructured WO3 thin film as a new anode material for lithium-ion batteries

Nanostructured WO3 thin film has been successfully fabricated by radio-frequency magnetron sputtering method and its electrochemistry with lithium was investigated for the first time. The reversible discharge capacity of WO3/Li cells cycled between 0.01 V and 4.0 V was found above 626 mAh/g during the first 60 cycles at the current density 0.02 mA/cm2. By using X-ray diffraction, X-ray photoelectron spectroscopy, transmission electron microscopy and selected-area electron diffraction measurements, the reversible conversion of WO3 into nanosized metal W and Li2O was revealed. The high reversible capacity and good recyclability of WO3 electrode made it become a promising cathode material for future rechargeable lithium batteries.