One-step electrochemical preparation of graphene-based heterostructures for Li storage

We report a facile method to prepare nanoarchitectured metal oxides/graphene hybrids as both positive and negative electrodes for Li-ion batteries. The metal oxides/graphene hybrids were synthesized by deposition of metal oxides and exfoliation of graphene sheets in a one-step electrochemical process. The hybrid electrodes showed high specific capacities with excellent cycling stability. For example, the Fe ₂O ₃/graphene anode was able to deliver a discharge capacity of up to 894 mA h g ^-1 during the 50 ^th cycle at 0.3 C. Co ₃O ₄/graphene depicted a discharge capacity of 880 mA h g ^-1 during the 40 ^th cycle at 0.3 C. The V ₂O ₅/graphene cathode delivered a discharge capacity of 208 mA h g ^-1 during the 100 ^th cycle at 6.8 C.