Synthesis and properties of Li2MnO3-based cathode materials for lithium-ion batteries

Lithium-ion batteries have been wildly used in various portable electronic devices and the application targets are currently moving from small-sized mobile devices to large-scale electric vehicles and grid energy storage. Therefore, lithium-ion batteries with higher energy densities are in urgent need. For high-energy cathodes, Li2MnO3-LiMO2 layered-layered (M = Mn, Co, Ni) materials are of significant interest due to their high specific capacities over wide operating potential windows. Here, three Li2MnO3-based cathode materials with α-NaFeO2 structure were prepared by a facile co-precipitation method and subsequent heat treatment. Among these three materials, 0.3Li2MnO3·0.5LiMn0.5Ni0.5O2·0.2LiCoO2 shows the best lithium storage capability. This cathode material is composed of uniform nanosized particles with diameters ranging from 100 to 200 nm, and it could be charged to a high cutoff potential to extract more lithium, resulting in a high capacity of 178 mAh g−1 between 2.0 and 4.6 V with almost no capacity loss over 100 cycles.