Synthesis and characterization of spherical LiNi _0.8Co _0.1Mn _0.1O ₂ particles with a high tap-density

Spherical Ni _0.8Co _0.1Mn _0.1(OH) ₂ precursors with a high tap-density and a narrow size-distribution were synthesized via coprecipitation using NaOH and NH ₃·H ₂O as the precipitation and complexing agents. Spherical LiNi _0.8Co _0.1Mn _0.1O ₂ particles were then prepared by sintering the mixture of this precursor and LiOH·H ₂O. The prepared materials were characterized by XRD, SEM, TEM, TGA/DSC and galvanostatically charge/discharge tests. The results indicate that secondary spherulites of the precursors are formed by aggregation of crystals but not by elongated crystals. The reaction time shows a significant effect on the morphology, size-distribution and tap-density of the precursor. The LiNi _0.8Co _0.1Mn _0.1O ₂ powders calcined under 750°C for 16 h exhibit a spherical morphology with the highest tap-density (2.98 g/cm ³) and the largest initial discharge capacity (202.4 mAh/g). More than 92.3% of the capacity is retained after 40 cycles. In addition, the cell delivers a discharge capacity of 174.1 mAh/g at 3C rate.