Synergetic Effects of Al3+ Doping and Graphene Modification on the Electrochemical Performance of V2O5 Cathode Materials

Abstract A series of V 2 O 5 ‐based cathode materials that include V 2 O 5 and Al 0.14 V 2 O 5 nanoparticles, V 2 O 5 /reduced graphene oxide (RGO), and Al 0.16 V 2 O 5 /RGO nanocomposites are prepared by a simple soft chemical method. XRD and Raman scattering show that the Al ions reside in the interlayer space of the materials. These doping ions strengthen the VO bonds of the [VO 5 ] unit and enhance the linkage of the [VO 5 ] layers, which thus increases the structural stability of V 2 O 5 . SEM and TEM images show that the V 2 O 5 nanoparticles construct a hybrid structure with RGO that enables fast electron transport in the electrode matrix. The electrochemical properties of the materials are studied by charge–discharge cycling, cyclic voltammetry, and electrochemical impedance spectroscopy. Of all the materials tested, the one that contained both Al ions and RGO (Al 0.16 V 2 O 5 /RGO) exhibited the highest discharge capacity, the best rate capability, and excellent capacity retention. The superior electrochemical performance is attributed to the synergetic effects of Al 3+ doping and RGO modification, which not only increase the structural stability of the V 2 O 5 lattice but also improve the electrochemical kinetics of the material.