High-performance of copper-doped vanadium pentoxide porous thin films cathode for lithium-ion batteries

In this work, porous Cu-doped V(2)O(5)nH(2)O thin film electrodes have been directly synthesized via low-temperature annealing and simple drop-casting method from V2O5/H2O2 sol with various concentration copper ion (Cu2+). It is interesting to find that the mass fraction of Cu2+ has effects on the morphologies, valence state of vanadium, and electrochemical performance of Cu-doped V(2)O(5)nH(2)O thin film. When the mass fraction of Cu2+ is 1wt.%, the obtained Cu-doped V(2)O(5)nH(2)O thin film electrode shows network porous nanostructure. Moreover, it still shows high discharge specific capacity of 344mAhg(-1) at a current density of 250mAg(-1). Excellent cycling stability with only 0.14% per cycle degradation during 104cycles can be obtained even at a high current density of 550mAg(-1). Improvement of electrochemical performance is attributed to unique network porous nanostructure, accelerating the lithium-ion transfer rate in the de-intercalation or intercalation process.