Enhanced Electrochemical Performance of Li-1.2[Mn0.54Co0.13Ni0.13]O-2 Enabled by Synergistic Effect of Li1.5Na0.5SiO3 Modification

Surface coating is effective in improving the electrochemical properties of layered lithium-rich Mn-based oxide-Li-1.2[Mn0.54Co0.13Ni0.13]O-2 (LLMO). In this work, a novel coating material-Na+ doped Li2SiO3 (forming Li1.5Na0.5SiO3) is selected to modify LLMO. By means of the modification, the Na+ doping is realized along with the Li2-xNaxSiO3 coating on the surface of Li1.2-xNax[Mn0.54Co0.13Ni0.13]O-2 (NLLMO). The higher electrochemical activity of Li2-xNaxSiO3 than Li2SiO3, and surface Na+ doping of LLMO, can significantly improve the battery performance of the LLMO cathode. Consequently, 1 wt% Li1.5Na0.5SiO3 modified LLMO exhibits much improved cycling stability than the others with the minimum voltage decay of only 0.198 V and the highest capacity retention of 83.9% after 100 cycles at 0.5C (1C = 200 mAh g(-1)). Moreover, it also exhibits an excellent rate performance (200.6 mAh g(-1) at 1C). The outstanding electrochemical performance of 1 wt% Li1.5Na0.5SiO3 modified LLMO sheds more light on improving the properties of Li-rich cathode materials.