Fabricated and improved electrochemical properties of layered lithium-rich Co-free manganese-based Li_1.2Mn_0.6Ni_0.2O₂ cathode material for lithium-ion batteries

To meet the development needs of high-performance and low-cost lithium-ion batteries, lithium-rich Co-free manganese-based cathode materials have become the primary choice for future power batteries based on the advantages of low cost and improved battery performance. Herein, Li_1.2Mn_0.6Ni_0.2O₂ is prepared by the high-temperature solid-state method. The impacts of calcination temperature, holding time, and heating rate on the microstructure and properties of cathode materials are systematically studied via orthogonal experiments. Results revealed that Li_1.2Mn_0.6Ni_0.2O₂ prepared by the high-temperature solid-state method at a calcination temperature of 900 °C, holding time of 12 h, and heating rate of 15 °C/min is ideal, with a smaller particle size and uniform particle distribution and a lower agglomeration degree, and the initial discharge specific capacity reaches 148.4 mAh·g⁻¹ at 0.1 C. The discharge specific capacity of 102.8 mAh·g⁻¹ is still maintained after 100 charge–discharge cycles. Among the various factors, holding time has the greatest influence on the lithium-rich Co-free manganese-based cathode material. The crystallinity, electrochemical properties, and microstructure of the material prepared at 12 h were considerably better than those prepared under other conditions. Test findings show that with a small particle size and uniform distribution, the synthesized cathode material has better rate and cycle performances.