Synthesis of sea-urchin shaped gamma-MnO2 nanostructures and their application in lithium batteries

Sea-urchin shaped gamma-MnO2 hierarchical structures have been synthesized using a facile hydrothermal method without employing any template or surfactant with mild conditions. The as-synthesized samples were characterized by instrumental analyses such as XRD, SEM, and EDXS. gamma-MnO2 sea-urchins are assembled from nanowires of 20 50 nm in width and up to 3 mu m in length. Electrochemical investigations indicate that the sea-urchin shaped gamma-MnO2 hierarchical nanostructures exhibit favorable performance compared to commercial manganese dioxide as cathode active materials in rechargeable Li-MnO2 cells. The sample retains a performance of 101 mA h g(-1) after 20 charge/discharge cycles.