Unveiling the role of trivalent cation incorporation in Li-rich Mn-based layered cathode materials for low-cost lithium-ion batteries

A simple solvothermal route was successfully implemented for fabrication of Li-rich Mn-based layered cathode Li1.15Ni0.15Co0.15Mn0.7M0.01O2 (LMLC) materials through incorporation of different trivalent cations (M3+: Al3+, Cr3+ or Fe3+). The structural properties of mixed solid solution of rhombohedral LiNiO2 phase and monoclinic Li2MnO3 phases were checked by X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). LMLC-Fe sample shows the highest coercivity Hc value of about 198.1 Oe, and the lowest dielectric constant εr about 74. LMLC-Cr sample exhibits the lowest activation energy (Ea = 0.163 eV) for electric conduction as a result of the smallest cell volume and particle size. LMLC-Al electrode material delivers the highest initial charge and discharge capacity of about 140 and 104 mAh/g at 0.1 C, respectively maintaining around 70% of the initial capacity at 0.1C. Both LMLC-Al and LMLC-Cr samples show better high rate capabilities than that of LMLC-Fe sample.