Rod-like hierarchical nano/micro Li_1.2Ni_0.2Mn _0.6O₂ as high performance cathode materials for lithium-ion batteries

Rod-like hierarchical nano/micro structured lithium rich materials (RH-LNMO), Li_1.2Ni_0.2Mn_0.6O₂, have been synthesized using a facile hydrothermal method. The as-prepared samples are characterized by X-ray diffraction (XRD), filed emission scanning electron microscopy (FESEM) and transmission electron microscope (TEM). The rod-like hierarchical structures (1-3 μm in width and 3-10 μm in length) are assembled by nanoparticles with average sizes of 20-150 nm. Electrochemical data demonstrates that lithium cells using this lithium rich material as the cathode exhibit excellent performances. This material retains a high discharge capacity of 212.5 mAh g^-1 (97% of the first discharge capacity) after 30 cycles at 1C-rate, and it yields an initial discharge capacity of 198 mAh g ^-1 at 2C-rate. The superior performance is attributed to the merits of the hierarchical nano/micro structures.