Hollow and hierarchical Li1.2Mn0.54Ni0.13Co0.13O2 micro-cubes as promising cathode materials for lithium ion battery

Based on the Mn0.806Co0.194CO3 precursors, Li1.2Mn0.54Ni0.13Co0.13O2 micro-cube (MC-LMNC) was prepared. The as-prepared sample is hollow and possesses a shell of about 200 nm, which is assembled by a series of nano particles (similar to 50 nm). X-ray diffraction and Raman spectroscopy confirmed that the materials obtained are well crystalline and have a good layered structure. The electron microscopy showed that the micro-cubes disperse uniformly and have a hierarchical structure. In comparison to the sample obtained by a sol-gel method (SG-LMNC), LNMC micro-cube has a much better electrochemical performance. The average discharge capacities for SG-LMNC sample are 276.6, 220.1, 155.8, 97.9, 66.7, and 40.3 mAh g(-1) at a 0.1, 0.2, 0.5, 1.0, 3.0, and 5.0 C respectively, while those for MC-LMNC are 302.5, 241.2, 190.5, 145.4, 103.8, and 70.6 mAh g(-1) at the same rates. EIS measurements confirmed that the diffusion coefficients for SG-LMNC and MC-LMNC are 1.13 x 10(-16) and 1.61 x 10(-16) cm(2) s(-1). The origin of the performance differences can be attributed to the different morphology, surface area, and pore size of the two samples, which has been verified by the BET analysis. (C) 2019 Elsevier B.V. All rights reserved.