Improving the electrochemical performance of Li1.2Mn0.54Ni0.13Co0.13O2 cathode through sodium doping

The application of the Li-rich Mn-based layered cathodes with high energy density is limited due to the capacity degradation and voltage decay during cycling. Herein, a modification strategy of sodium doping to enhance the electrochemical performance of the layered Li1.2Mn0.54Ni0.13Co0.13O2 (LMNC) cathode material synthesized by sol-gel and calcination is conducted in this paper. An appropriate amount of sodium doping changes the lattice constant and expands the lithium interlayer spacing of the layered cathode and still maintains well layered structure, exhibiting superior electrochemical performance such as cycling stability and rate capacity. The LMNC cathode doped with Na+ (x = 0.02) delivers initial discharge capacities of 265.2 mAh g−1 at 0.1 C and 223.0 mAh g−1 at 0.5 C, relatively decelerated voltage decay and high capacity retention after long-term cycles. This is attributed to the decrease of the charge-transfer resistance, the increase of the Li+ diffusion coefficient, well layered structural and phase stability. © 2021 Elsevier Ltd