Study On Synthesis Of High Tapping Density Spherical Nickel Hydroxide

In this paper, we prepared a spherical nickel hydroxide with high tapping density by ordinary stirred reactor. We studied in two aspects after obtaining optimum processing conditions in a stirred reactor. One, we selected the appropriate of additive and the amount of additive through comparing the electrical properties. The other one, we can use Rotor-stator Reactor (RSR) to prepare a spherical nickel hydroxide. RSR can improve mixing of the reaction mass. RSR can strengthen the reaction mixture. We selected optimum process conditions, the appropriate of additive and the amount of additive by experiments. The structure of nickel hydroxide was charactered by XRD, SEM, TG-DTA and the particle size distribution. At the same time, electrical properties of nickel hydroxide were studied by cyclic voltammetry and charge-discharge tests.Firstly, we prepared high tapping density spherical nickel hydroxide by ordinary stirred reactor. Through comparing tapping density and electrical properties of nickel hydroxide, we selected optimum processing conditions:0.4 mL�min-1 of dropping rate,11.8 of the pH of the reaction system,50?,6 M of ammonia concentration,16 h of aging time and 1.2 M of the nickel ion concentration. The tapping density of the sample we prepared was 2.05 g�cm-3. Charging capacity of the sample was 263 mAh�g-1. ?Ea,o of the sample was 0.10 V. ?Ea,c of the sample was 0.48 V.When preparing different metal-doped spherical nickel hydroxide, we selected the appropriate of additive and the amount of additive by different metal-doped experiments:1% cobalt-doped,1% zinc-doped,1% magnesium-doped. The sample has excellent electrical performance at 25? and 65?. The sample offers a high discharge specific capacity of 292 mAh�g-1 at 25?.The ?Ea,c of the sample is 0.36 V at 25?. The ?Ecf,o of the sample is 0.14 V at 25?. The sample offers a high discharge specific capacity of 288 mAh�g-1 at 65?.The ?Ea,c of the sample is 0.38 V at 65?. The ?Ec,o of the sample is 0.12 V at 65?.When used RSR to prepare nickel hydroxide, we studied circulation rate and speed. We selected the optimum processing conditions by experiments: 1120 r�min-1 of speed and 600mL�min-1 of circulation rate. The tapping density of the sample we used RSR was 1.62 g�cm-3. The charging capacity of the sample was 262 mAh�g-1.