Thermal, electrochemical and In-Situ Structural Study of Stabilized LiNi_yCo_1-y-z M_zO_2 (M = Al and Mg) Lithium-Ion Cathode Materials Prepared by A Soft Chemistry Route

摘要

Doped LiNI_yCo_1-y-z M_zO_2, with M = Al and Mg, and z = 0.04 mole ratio, were prepared using a soft chemistry route. The thermal behaviour of these materials was studied to confirm their stability using differential scanning calorimentry (DSC). The reversibility and rate capabilites of the cathodes in lithium cells were characteried using electrochemical measurement. A recently developed in-situ X-ray technique was used to investigated the structural properties of the oxides upon galvanostatic cycling. The addition of Al and Mg, as dopants, was demonstrated to dramatically improve the stability of LiNi_0.8Co_0.2O_2.