Technical Study Of Preparing High Density Nickel Hydroxide In Batteries

The preparation and structure properties of nickel hydroxide as a positive active material for the new types of foam and fibrous nickel electrodes and high capacity MH-Ni alkaline rechargeable batteries were studied.First, through analyzing different stable contants of nickel ion with other coordination compands several coordination compands fitted to prepare Ni(OH)2 are choosed. And then it is believed that NH3 H2O is the better coordination compand via experiments with these coordination compands.Second, thermodynamics model is set up according to balancing concentration relation. The numerical relationship of [Ni2]-[NH3]-pH and the curves of them are obtained. Based on the curves the range of [NH3] is found.Third, Ni(OH)2 prepared in different conditions (pH value, entering NH3 quantity, reaction hours, reaction temperature, stirring speed, deposited effect) are analyzed and contrasted in the all kinds of physical properties (shape, average diameter of particles and distributing of particle diameter, stack density) and crystal structure. At last, we got the scopes of various technical conditions in order to prepare high density Ni(OH)2: pH value is 10.5-10.9, reaction hours are over 8 hours, NH3/NaOH=1.2, voltage is about 200V and reaction temperature is 45~65. in addition, the placing and additives are also studied.