| Abstract
| - LiNi1-yTiyO2 (y ≤ 0.15) layered oxides were synthesized at high temperature by solid-state reactions. Rietveld refinements of their X-ray and neutron diffraction patterns showedthat these phases were characterized by an α-NaFeO2-type structure with the followingcationic distribution: (Li1-zNi2+z)3b(Ti4+tNi2+t+zNi3+1-z-2t)3aO2 [t = y(1 + z)]. The amount ofNi2+ ions in the lithium site increases with y. A magnetic study confirmed the presence ofparamagnetic ions in the interslab space and, therefore, the cationic distribution. Thesematerials used as positive electrode in lithium batteries show reversible behavior. A largedecrease of the capacity is observed with increasing y, because of the presence of extra nickelions in the lithium sites. For the “LixNi0.95Ti0.05O2” composition, 144 mA h/g are obtained indischarge at the 14th cycle at the C/20 rate. The “LixNi1-yTiyO2” phases were characterizedfor y = 0.05 and 0.10: the simultaneous presence of titanium ions in the slab and of asignificant amount of extra nickel ions in the lithium sites prevents phase transitions uponcycling.
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