Improving the cathode properties of Ni-rich LiNi0.6Co0.2Mn0.2O2 at high voltages under 5 C by Li2SiO3 coating and Si4+ doping

Cathode materials based on zLi2SiO3@LiNi0.6Co0.2Mn0.2O2 (z = 0, 0.03, 0.05, 0.08) (where “@” denotes “coated on the surface of”) have been successfully prepared via a syn-lithiation strategy. The cycling performance of LiNi0.6Co0.2Mn0.2O2 has been effectively enhanced by coating a Li2SiO3 thin film. Compared to the 81 mAh/g discharge capacity of the pristine materials, the 5 mol% Li2SiO3-coated LiNi0.6Co0.2Mn0.2O2 electrode exhibits 31% higher discharge capacity between 2.5 V and 4.5 V at a rate of 5 C. The reason for the improved cycling performance of LiNi0.6Co0.2Mn0.2O2 is Li2SiO3 coating and Si4+ doping, which stabilizes the structure, suppresses the direct contact between the active materials and electrolytes, enhances lithium ion diffusion at the electrode/electrolyte interface, and prevents the pulverization of active materials during repeated charging/discharging.