Mesoporous crystalline β-MnO₂ - A reversible positive electrode for rechargeable lithium batteries

The synthesis of mesoporous β-MnO₂ with a highly ordered pore structure and highly crystalline walls, which acts as a reversible positive electrode for rechargable lithium batteries, was investigated. The technique involved a mesoporous silica template possessing a highly ordered 3D pore structure with an aqueous solution of Mn(NO₃)₂ and a Transmission electron microscopy (TEM) data. The characterization of the mesostructure was carried out by N₂ sorption measurements, which projected a type IV isotherm, consistent with mesoporosity. The pore size distribution, which was derived from the desorption branch of the isotherm, was narrow and revolved around a diameter of 3.65 mm. Mesoporous β-MnO ₂ projected the property to accommodate reversibly a large amount of Li on intercalation, with 81% capacity retention on increasing the rate 20-fold after 50 cycles.