A high-performance Cu-doped vanadium pentoxide thin-film cathode for lithium-ion batteries

Cu-doped V2O5 thin film cathodes are successfully fabricated by an electrodeposition method. The cathode with 1 wt.% Cu-doped shows excellent performance with a specific discharge capacity of up to 362 mAh/g, representing ~86.2% of the theoretical specific capacity (420 mAh/g), and relatively low polarization in charge/discharge processes. The highest discharge capacity is increased by 27% (73 mAh/g) compared to a pure V2O5 cathode. A moderate level of Cu doping can promote the formation of a three-dimensional nanoscale net structure, which can effectively increase the specific surface area of the V2O5 cathode and improve the transport capacity of Li ions. The Cu ions strengthen the V-O bonding of the [VO5] unit and the association of the [VO5] plate. More small polaritons are generated by coupling the negative charge on the V4+ cation and the lattice deformation caused by the Cu2+ cation, resulting in a higher electronic conductivity.