Effect of synthetic routes on the rate performance of Li-rich layered Li1.2Mn0.56Ni0.12Co0.12O2

Abstract

Different morphologies and compositions of Li-rich layered Li_1.2Mn_0.56Ni_0.12Co_0.12O₂ (LMNCO) materials are successfully synthesized by solvothermal and coprecipitation methods. The samples synthesized by the solvothermal method possess a 3D porous hierarchical microstructure and designed chemical components, while those prepared through the coprecipitation method present partially agglomerated nanoplates and Mn-deficiency. When used as a cathode for lithium ion batteries (LIBs), the LMNCO synthesized by the solvothermal method exhibits superior performances to that prepared by the coprecipitation method, especially in terms of discharge capacity and rate capability: it delivers a discharge capacity of 292.3 mA h g⁻¹ at 0.2 C and 131.1 mA h g⁻¹ even at a rate as high as 10 C. The excellent electrochemical performances of the LMNCO synthesized by the solvothermal method are associated with a synergistic effect of the well-defined morphology and well-ordered structure with good homogeneity and designed stoichiometry. The results demonstrate that the facile solvothermal method may offer an attractive alternative approach for the preparation of Li-rich layered cathode materials with high rate capability.