A core-shell porous MnO2/Carbon nanosphere composite as the anode of lithium-ion batteries

In this work, hollow carbon nanospheres (HCN) loaded with MnO2 (denoted as MnO2@HCN) are investigated as an anode material for lithium-ion batteries. HCN is developed by treatment of 3-aminophenol and formaldehyde resin. MnO2 is loaded on the outer surface of HCN via the reduction of KMnO4 to form porous core-shell structures. SEM, TEM and XRD characterizations indicate that the MnO2@HCN has a spherical morphology with a core consisting of porous carbon nanoparticles and a shell consisting of MnO2 nanoparticles. The charge-discharge tests demonstrate that this unique configuration endows the resulting MnO2@HCN with excellent electrochemical performance as anode of a lithium ion battery, delivering a capacity of 604 mA h g−1 at 0.3 C after 200 cycles, compared to 211 mA h g−1 of the HCN. The porous structure consisting of small nanoparticles provides MnO2@HCN with high surface area and good structural stability, facilitating lithium insertion/extraction, which yields excellent cycling stability of the MnO2@HCN electrode.