Facile fabrication of MnO2 nanorod/graphene hybrid as cathode materials for lithium batteries

Highlights: • The MG-300 was synthesized by a facile and effective thermal annealing method. • The SEM and TEM images showed that the MnO2 nanorods were well anchored on the surface of graphene. • The MG-300 delivered the best electrochemical performance among all the as-prepared samples. • The MG-300 showed a high initial capacity of 241 mAh g−1 at 0.1 C and maintained at a capacity of 158.3 mAh g−1 after 100 cycles. -- Abstract: A facile thermal annealing method is demonstrated to fabricate the MnO2 nanorods/graphene hybrid. The MnO2 nanorods are well anchored on the graphene, confirmed by the scanning electron microscopy and transmission electron microscopy images. The hybrid annealed at 300 °C (MG-300) shows a high initial discharge capacity of 241 mAh g−1 at 0.1 C with a graphene loading rate of 9%. In addition, it shows good cycling stability and maintains a capacity of 158.3 mAh g−1 after 100 cycles in the potential window between 2 and 3.5 V. The MG-300 exhibits the best electrochemical performance among all the materials, which is due to the high electronic conductivity of graphene and the MnO2 nanorods which is consisted of γ-MnO2 and β-MnO2