Porous V2O5/RGO/CNT hierarchical architecture as a cathode material: Emphasis on the contribution of surface lithium storage

Abstract

A three dimensional vanadium pentoxide/reduced graphene oxide/carbon nanotube (3D V2O5/RGO/CNT) composite is synthesized by microwave-assisted hydrothermal method. The combination of 2D RGO and 1D CNT establishes continuous 3D conductive network, and most notably, the 1D CNT is designed to form hierarchically porous structure by penetrating into V2O5 microsphere assembly constituted of numerous V2O5 nanoparticles. The highly porous V2O5 microsphere enhances electrolyte contact and shortens Li+ diffusion path as a consequence of its developed surface area and mesoporosity. The successive phase transformations of 3D V2O5/RGO/CNT from α-phase to ε-, δ-, γ-, and ω-phase and its structural reversibility upon Li+ intercalation/de-intercalation are investigated by in situ XRD analysis, and the electronic and local structure reversibility around vanadium atom in 3D V2O5/RGO/CNT is observed by in situ XANES analysis. The 3D V2O5/RGO/CNT achieves a high capacity of 220 mAh g−1 at 1 C after 80 cycles and an excellent rate capability of 100 mAh g−1 even at a considerably high rate of 20 C. The porous 3D V2O5/RGO/CNT structure not only provides facile Li+ diffusion into bulk but contributes to surface Li+ storage as well, which enables the design of 3D V2O5/RGO/CNT composite to become a promising cathode architecture for high performance LIBs.

V2O5 and its Carbon‐Based Nanocomposites for Supercapacitor Applications

“…The technique provides a fast and homogeneous internal heating of the material/system unlike traditional surface heat transferring methods. Graphene obtained by this technique are larger‐sized, having controlled morphology with appreciable amounts of residual surface functional groups favoring both strong anchoring of metal oxides along with faster charge transport characteristics; ideally suitable for high electrochemical storage efficiency …”

Hybrid Electrode Innovations in Triple and Quadruple Dimensions for Lithium‐Ion Batteries

“…Similar trends were observed in a study of Palanisamy et al . who used RGO and CNT to modify V 2 O 5 NPs in a hierarchical nanoarchitecture.…”

Extended Limits of Reversible Electrochemical Lithiation of Crystalline V2O5

“…Active development of the approaches for synthesis of nanostructured materials revitalized interest to vanadium pentoxide as a host for lithium storage . Moreover, preparation of V 2 O 5 composites with nanostructured carbon additives like carbon nanotubes or graphene‐like materials (mainly, reduced graphene oxide – RGO) has recently also come in focus as these nanostructured additives were found to alter the ionic and electronic transport in the electrode material affecting the phase transition character and compositional phase stability limits.…”