LixNi0.7Co0.3O2 electrode material:: Structural, physical and electrochemical investigations

The layered LiNi0.7Co0.3O2 cathode material was synthesized by the combustion method using sucrose as fuel at 800 degrees C for 1 h, which leads to homogeneous size distribution with sub-micron particle size. The characterization of this material was realized using X-ray diffraction, scanning electron microscopy and completed by magnetic measurements. The Rietveld refinement shows the presence of 2.6% extra nickel in the interslab space. The presence of nickel ions in the lithium layers was confirmed by magnetization measurements. The 90 degrees Ni-O-Ni ferromagnetic coupling is the main magnetic interactions. Lithium extraction from this phase occurs without major structural modifications. Cycling tests have shown a very good cycling stability at various current rates. Furthermore, this material delivers high reversible capacity of about 150 mAh/g in the 2.8-4.4 V range at the C/20. (c) 2008 Elsevier Ltd. All rights reserved.