A Co-free layered LiNi0.7Mn0.3O2 cathode material for high-energy and long-life lithium-ion batteries

A Co-free layered cathode material, LiNi0.7Mn0.3O2, was synthesized using the co-precipitation method. The optimum conditions for the cathode were determined on the basis of particle size. The relationship between the cathode material's particle size and its lithium-ion battery performance was studied on the basis of the capacity and cyclability. The LiNi0.7Mn0.3O2 material exhibited a high reversible capacity of 176 mA h g−1 and a high cyclability, with 98% capacity retention after 40 cycles under the optimum conditions with a specific reaction time. A mechanism based on the structures and morphologies of the synthesized cathode materials is proposed.