Enhanced Electrochemical Properties of Zr4+-doped Li1.20[Mn0.52Ni0.20Co0.08]O2 Cathode Material for Lithium-ion Battery at Elevated Temperature

Abstract

The typical co-precipitation method was adopted to synthesized the Li-excess Li1.20[Mn0.52-x Zr x Ni0.20Co0.08]O2 (x = 0, 0.01, 0.02, 0.03) series cathode materials. The influences of Zr4+ doping modification on the microstructure and micromorphology of Li1.20[Mn0.52Ni0.20Co0.08]O2 cathode materials were studied intensively by the combinations of XRD, SEM, LPS and XPS. Besides, after the doping modification with zirconium ions, Li1.20[Mn0.52Ni0.20Co0.08]O2 cathode demonstrated the lower cation mixing, superior cycling performance and higher rate capacities. Among the four cathode materials, the Li1.20[Mn0.50Zr0.02Ni0.20Co0.08]O2 exhibited the prime electrochemical properties with a capacity retention of 88.7% (201.0 mAh g-1) after 100 cycles at 45 °C and a discharge capacity of 114.7 mAh g-1 at 2 C rate. The EIS results showed that the Zr4+ doping modification can relieve the thickening of SEI films on the surface of cathode and accelerate the Li+ diffusion rate during the charge and discharge process.