Synthesis of V 2 O 5 /C core/shell arrays on graphene foam for electrochemical energy storage

Abstract V 2 O 5 -based materials are regarded as promising cathode materials for lithium-ion batteries (LIBs) because of their larger theoretical capacities than commercial cathode materials. Herein we develop a united solvothermal-chemical vapor deposition method for construction of bind-free V 2 O 5 /C core/shell arrays on the graphene foams positive electrodes of LIBs. Active V 2 O 5 nanoflakes with thicknesses of 10–15 nm are wrapped by ultrathin carbon layer of 2–4 nm forming core/shell arrays on the GF skeleton. The unique core/shell architecture can provide short ion/electron diffusion paths and substantial protection shell for the active materials, thus leading to accelerated electrochemical kinetics and enhanced cycling stability. A noticeable initial capacity of 290 mAh g −1 at 1C in the voltage range of 2.0–4.0 V and 217 mAh g −1 at 6C after 1000 cycles could be obtained for the GF + V 2 O 5 /C electrode, much better than its GF + V 2 O 5 counterpart.