Synthesis, structural, magnetic and electrochemical properties ofLiNi1/3Mn1/3Co1/3O2prepared by a sol-gel method using table sugar aschelating agent
Résumé
tTable sugar (sucrose) was used as a new and cheap chelating agent to prepare LiNi1/3Mn1/3Co1/3O2. X-ray diffraction (XRD) shows that the powder adopts the -NaFeO2layered structure with space groupR3m. The high value of c/a above 4.97 indicates a well-ordered rhombohedral lattice. The refined degreeof cationic mixing of 2.4% remains fixed upon cycling. The fatigue of the material used as a positiveelectrode of a Li-cell has been investigated by scanning and transmission electron microscopy (SEM andTEM) as well as the magnetic measurements in the initial, charged and discharged state at low C/10 rateover the 10th first cycles. Small cracks are observed after cycling, despite the low C-rate and the voltagerange limited to 3.0-4.2 V in which only the Ni is electrochemically active. This fatigue, however, hasno sizeable impact on the capacity: the initial capacity ≈150 mAh g−1was retained at the 10th cycle