Graphene foam supported V2O5/N-C core/shell arrays as advanced cathode for lithium ion storage

Abstract

It is an eternal goal to pursue high-performance electrode materials with both high energy & power densities. Herein we report lightweight bind-free positive electrodes by combing V2O5/N-doped carbon (N-C) core/shell arrays and graphene foam (GF) via solvothermal and self-polymerization methods. Active multileveled V2O5 nanoflakes with thicknesses of 10 nm are intimately wrapped by ultrathin N-doped carbon layer of ∼2 nm forming core/shell arrays on the GF skeleton. Such an integrated electrode not only possesses merits of porous nanostructures with short ion/electron diffusion paths, but also shows improved structural stability and omni-bearing charge transfer ways for V2O5. As cathode of lithium ion batteries (LIBs), the GF+V2O5/N-C core/shell arrays exhibit superior Li ion storage properties with a noticeable initial capacity of 293 mAh g−1 at 1C in the voltage range of 2.0–4.0 V and 223 mAh g−1 at 5 C after 1000 cycles, better than the GF+V2O5 nanoflake counterpart. It is prospected that such integrated electrode design strategy can also be extended to fabricate other advanced positive electrodes for applications in energy storage.