Delithiated LiyCo0.8Ni0.1Mn0.1O2 cathode materials for lithium-ion batteries: Structural, magnetic and electrochemical studies

• LiNi0.1Mn0.1Co0.80O2 electrode material was prepared by the combustion method.
• High discharge capacities of 180 mAh g− 1 at C/2 and 145 mAh g− 1 at 4C were reached.
• No structural transition was evidenced during delithiation (ΔV ≤ 10%).
• EPR and SQUID studies show the oxidation of Co3 + in addition of that of Ni2 +.
• Magnetic measurements evidenced an insulator–metal transition at high delithiation.

LiCo0.8Ni0.1Mn0.1O2 positive electrode material was prepared via the combustion method followed by a thermal treatment at 900 °C for 1 h. A systematic study has been performed to investigate the structural changes of LiCo0.8Ni0.1Mn0.1O2 upon chemical lithium extraction. X-ray diffraction (XRD), electronic paramagnetic resonance (EPR), and magnetic susceptibility measurements were performed. These experiments provided a detailed picture of the whole delithiation process. Not only oxidation of Ni2 + ions but also some Co3 + ions were evidenced at the beginning of the delithiation process. Further lithium extraction induces an insulator to metal transition for the composition Li0.3Co0.8Ni0.1Mn0.1O2 as shown by the plot of χ− 1 (T) vs. T, which is similar to that reported for LiyCoO2. The electrochemical performances of the LiCo0.8Ni0.1Mn0.1O2 sample were measured at different current rates in the 3–4.5 V potential range. This material exhibits good discharge capacity of 180 mAh g− 1 and a columbic efficiency approaching 96%.