Preparation and Cyclic Performance of Li_1.2(Fe_0.16Mn_0.32Ni_0.32)O₂ Layered Cathode Material by the Mixed Hydroxide Method

摘要

Layered Li1.2(Fe0.16Mn0.32Ni0.32)O2 was prepared by the mixed hydroxide method at various temperatures. Xray diffraction (XRD) pattern shows that this material has a α-NaFeO2 layered structure with R3m space group and that cation mixing is reduced with increasing synthesis temperature. Scanning electron microscopy (SEM) reveals that nano-sized Li1.2(Fe0.16Mn0.32Ni0.32)O2 powder has uniform particle size distribution. X-ray absorption near edge structure (XANES) analysis is used to study the local electronic structure changes around the Mn, Fe, and Ni atoms in this material. The sample prepared at 700 °C delivers the highest discharge capacity of 207 mAhg−1 between 2-4.5 V at 0.1 mAcm−2 with good capacity retention of 80% after 20 cycles.