Synthesis and Morphological Control of Nickel Hydroxide for Lithium−Nickel Composite Oxide Cathode Materials by an Eddy Circulating Precipitation Method

Spherical nickel hydroxide with high density was synthesized via an eddy-circulating precipitation method, in which a Ni(NO 3 ) 2 solution was reacted with a NaOH solution at 65−70 °C, and NH 4 NO 3 −NH 3 ·H 2 O was used as a buffer reagent. The resulting nickel hydroxide particles, with a tap density of 2.20 g/cm 3 and the average particle size of 30.6 μm, are aggregated by the granular crystallites. The morphology of the crystallite can be controlled by changing the anions. The LiNi 0.8 Co 0.2 O 2 that has been prepared using this nickel hydroxide shows excellent electrochemical performance, which delivers an initial discharge capacity of 190.90 mAh/g at a current rate of 25 mA/g between 3.0 V and 4.35 V and exhibits good cycle stability.