Enhanced Electrochemical Properties of Zr-doped Li[MnNiCo]O Cathode Material for Lithium-ion Battery at Elevated Temperature.

The typical co-precipitation method was adopted to synthesized the Li-excess Li[MnZr NiCo]O (x = 0, 0.01, 0.02, 0.03) series cathode materials. The influences of Zr doping modification on the microstructure and micromorphology of Li[MnNiCo]O cathode materials were studied intensively by the combinations of XRD, SEM, LPS and XPS. Besides, after the doping modification with zirconium ions, Li[MnNiCo]O cathode demonstrated the lower cation mixing, superior cycling performance and higher rate capacities. Among the four cathode materials, the Li[MnZrNiCo]O exhibited the prime electrochemical properties with a capacity retention of 88.7% (201.0 mAh g) after 100 cycles at 45 °C and a discharge capacity of 114.7 mAh g at 2 C rate. The EIS results showed that the Zr 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.