Enhanced Electrochemical Performance of Li_1.2[Mn_0.54Co_0.13Ni_0.13]O₂ Enabled by Synergistic Effect of Li_1.5Na_0.5SiO₃ Modification

Abstract Surface coating is effective in improving the electrochemical properties of layered lithium‐rich Mn‐based oxide‐Li_1.2[Mn_0.54Co_0.13Ni_0.13]O₂ (LLMO). In this work, a novel coating material‐Na⁺ doped Li₂SiO₃ (forming Li_1.5Na_0.5SiO₃) is selected to modify LLMO. By means of the modification, the Na⁺ doping is realized along with the Li_2−xNa_xSiO₃ coating on the surface of Li_1.2−xNa_x[Mn_0.54Co_0.13Ni_0.13]O₂ (NLLMO). The higher electrochemical activity of Li_2−xNa_xSiO₃ than Li₂SiO₃, and surface Na⁺ doping of LLMO, can significantly improve the battery performance of the LLMO cathode. Consequently, 1 wt% Li_1.5Na_0.5SiO₃ 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% Li_1.5Na_0.5SiO₃ modified LLMO sheds more light on improving the properties of Li‐rich cathode materials.