Electrochemical performance of yttrium substituted LiY(x)Ni(1-x)O2 (0.00 < or = X < or = 0.20) cathode materials for rechargeable lithium-ion batteries.

: Pristine LiNiO2 and yttrium substituted LiY(x)Ni(1-x)O2 (0.00 < or = X < or = 0.20) cathode materials were synthesized by sol-gel technique using aqueous solutions of metal nitrates and tartaric acid as a chelating agent. Physical properties of synthesized materials were characterized by using X-ray diffraction analysis (XRD), Scanning electron microscopy (SEM) and Transmission electron microscopy (TEM). X-ray powder diffraction analysis showed an increase in lattice parameters with increasing yttrium content yttrium occupies within the layer. SEM and TEM analyses were used to visualize the nature and surface morphological aspects of the oxides. Electrochemical studies were made for the assembled cells using galvanostatic charge/discharge studies discharge rate 0.5 C in the potential range between 3 and 4.5 V. Among them, LiY0.15Ni0.85O2 behaved much better, losing about 5% of its initial capacity (195 mA h g(-1)) after 60 cycles at 185 mA h g(-1). While the pristine LiNiO2 lost about 10% of its initial capacity (164 mA h g(-1)). The substitution of Ni with yttrium, in LiY0.15Ni0.85O2 enhanced the high discharge capacity, good reversibility and best electrochemical performance of rechargeable lithium-ion batteries.