Study On The Process For Preparation Of Cobalt Carbonate With Low Chlorine

Li-ion battery possesses intrinsic advantages of high specific energy, long recycling life and low self-discharge rate, and it is now considered as the competitive power sources for various applications ranging from microelectronics, electric vehicles to space missions. Due to the rapid development of communications and traffic industry in recent years, the consumption of cobalt for battery has already exceeded that for hard alloy industry, and the trade of battery has become the first consumption industry of cobalt in our country. The demand for cobalt carbonate, which is the precursor of LiCoO2 used as the raw material of Li-ion battery, is increasing constantly.At present, there are some problems in the preparation and study for cobalt carbonate at home and abroad. The cobalt carbonate powder with high chlorine concentration will bring adverse effects on the capacity, capacity retention, charge and discharge performance. Cobalt carbonate powder also exhibits poor stability, filtering and shape. The explosive demand for cobalt carbonate has brought about a technical improvement in product with high-purity, reasonable deposition process.In this paper, using CoCl2 as the raw material, and NaCO3 as the precipitation reagent, the cobalt carbonate power was synthesized by the method of liquid-phrase precipitation. Firstly, the thermodynamic possibility of preparation in aqueous solution was analysed. Secondly, in order to get the optimal synthetical process conditions, the influence of preparing procedures, such as temperature, initial concentration, pH value and adding way of reactants, on the morphology and content of chlorine was investigated.Electrodialysis was introduced to remove chloride from cobalt carbonate at room temperature in this paper. Firstly, the dynamics of electrodialysis was analysed.