Properties of LiNi1/3Co1/3Mn1/3O2 cathode material synthesized by a modified Pechini method for high-power lithium-ion batteries

Abstract

Layered nano-structured LiNi1/3Co1/3Mn1/3O2 cathode materials were synthesized in air by a modified Pechini method. The crystal structure and surface morphology of the samples were investigated by X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM). It was found that Li/Ni disorder and particle size of the samples are highly dependent on the synthesis temperature. Magnetic properties of the samples were investigated by SQUID magnetometry to further study the cation disorder of the material. The electrochemical properties of the LiNi1/3Co1/3Mn1/3O2/Li cells were investigated by charge/discharge measurements at different C rates. Although the samples synthesized at low temperatures are composed of nano-sized particles, the reversible capacity is relatively low due to the high degree of Li/Ni disorder. The cycle performance of the samples improves as the synthesis temperature increases probably due to the decreased surface area and improved structural stability. The rate capability of the samples depends on both particle size and Li/Ni disorder. The sample synthesized at 900 °C with relative small particle size and low degree Li/Ni disorder exhibited the best rate capability. © 2009 Elsevier B.V. All rights reserved.