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

Abstract

• 0.3Li 2 MnO 3 ·0.5LiMn 0.5 Ni 0.5 O 2 ·0.2LiCoO 2 was synthesized by a co-precipitation method. • The preparation method is simple and this material is inexpensive due to the high contents of Mn and Ni. • The material could be charged to a high potential to extract more lithium without structural damage. • A relatively high capacity of 178 mAh g −1 is delivered between 2.0 and 4.6 V with excellent cycling performance. 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, Li 2 MnO 3 –LiMO 2 layered–layered (M = Mn, Co, Ni) materials are of significant interest due to their high specific capacities over wide operating potential windows. Here, three Li 2 MnO 3 -based cathode materials with α-NaFeO 2 structure were prepared by a facile co-precipitation method and subsequent heat treatment. Among these three materials, 0.3Li 2 MnO 3 ·0.5LiMn 0.5 Ni 0.5 O 2 ·0.2LiCoO 2 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.