Hierarchical micro−nanostructured and Al3+−doped Li1.2Ni0.2Mn0.6O2 active materials with enhanced electrochemical properties as cathode materials for Li−ion batteries.

Li 1.2 Ni 0.2–x Mn 0.6–x Al 2x O 2 (x = 0, 0.01, 0.02, 0.03) electrode materials with hierarchical micro−nanostructures are synthesized via a porous polypropylene (PP) membrane as hard template. The physical and electrochemical measurements of the samples are systematically investigated to reveal the effects of the Al3+–doping on the electrochemical properties and physical characteristics. The test results show that the Li 1.2 Ni 0.18 Mn 0.58 Al 0.04 O 2 (x = 0.02) sample delivers the highest specific charge/discharge capacities and an improved rate capabilities for the enhanced the structure stability, reduced the charge transfer resistance and improved the diffusion coefficient of lithium ions. Hierarchical micro−nanostructured Li 1.2 Ni 0.2–x Mn 0.6–x Al 2x O 2 (x = 0, 0.01, 0.02, 0.03) electrode materials with sheet−like structures are synthesized via a porous polypropylene membrane as hard template. The effects of morphology characteristics and doping amount of Al3+ on the electrochemical properties and physical characteristics of the samples (e.g., phase composition, element composition and valence states, electrode reaction kinetics, charge/discharge capacities, cycling life, rate capability) are measured systematically in this work. The doping of Al3+ does not change the crystal structure of the Li 1.2 Ni 0.2 Mn 0.6 O 2 material, and the Li 1.2 Ni 0.18 Mn 0.58 Al 0.04 O 2 (x = 0.02) sample delivers the high specific charge/discharge capacities and the improved rate capabilities. Simultaneously, this method is suitable to synthesize other multi–component electrode materials with porous sheet–like structures. Unlabelled Image [ABSTRACT FROM AUTHOR]