Facile synthesis of nanoporous γ-MnO2 structures and their application in rechargeable Li-ion batteries

In this work, we report on the preparation of nanoporous gamma-MnO2 with different morphologies and their application in rechargeable Li-ion batteries. Nanoporous gamma-MnO2 has been successfully synthesized via a facile route using a hydrothermal treatment and sequential thermal decomposition without employing any template or surfactant. Through simply altering the reactant, nanoporous hollow microspheres and nanocubes can be selectively prepared. The influence caused by different reaction conditions on the structure and morphology of the products has been discussed in detail. It is found that the reactant NH4HCO3 and hydrothermal treatment are necessary for preparing the hollow microspheres. The thermal decomposition of the precursor leads to formation of the nanoporous structure. Both the as-prepared gamma-MnO2 hollow microspheres and the nanocubes exhibit promising electrochemical properties as the anode materials of rechargeable Li-ion batteries. In particular, the initial reversible capacity for the hollow microspheres and nanocubes were 1071.1 mAh g(-1) and 1041.9 mAh g(-1), respectively, showing their potential application in Li-ion batteries.