Method for producing lithium cobaltite by preparing hydroxyl trivalent cobalt oxide through wet chemical reaction

Abstract

The invention discloses a method for producing lithium cobaltite by preparing hydroxyl trivalent cobalt oxide through wet chemical reaction. The method comprises the following steps of: preparing cobalt salt solution and sodium hydroxide solution; adding ammonia water serving as a complexing agent and stirring to generate cobaltous hydroxide slurry; adding sodium hypochlorite solution to oxidize the cobaltous hydroxide slurry; filtering, washing and drying to obtain a hydroxyl trivalent cobalt oxide precursor; uniformly mixing the precursor and lithium carbonate and then sintering to obtain a lithium cobaltite product; crushing the lithium cobaltite, then adding oxides of Ti, Mg and Al, serving as additives, into a muffle furnace and then sintering to perform doping treatment; and crushing and grading to obtain a product. By adopting the method, the need of a high-temperature oxidation step in the conventional synthesis process of the lithium cobaltite from the bivalent cobalt compound is avoided, air or oxygen is not required to be introduced in a sintering process, and influence of oxygen diffusion on reaction is avoided; and the method has the advantages of quick sintering reaction, low energy consumption, high capacity and high product quality.

Description

technical field [0001] The invention relates to a method for producing lithium cobaltate by preparing cobalt trivalent oxide of hydroxyl by wet chemical reaction. Background technique [0002] In order to gradually solve the three major problems of energy shortage, greenhouse gas and air pollution that restrict the current economic development, lithium-ion batteries, as an energy storage device, have high working voltage, high energy density, long cycle life, low self-discharge rate, No memory effect, no environmental pollution and other advantages. In the past ten years, lithium-ion batteries have achieved rapid development in technology, production, and market, and have formed a large emerging industry, which has attracted more and more attention from all aspects; at present, lithium-ion battery cathode materials mainly include lithium cobaltate and manganese acid. Lithium, nickel-cobalt lithium manganese oxide ternary materials, lithium iron phosphate, among them, the li...

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Problems solved by technology

[0005] During the reaction process, it is necessary to introduce air or oxygen to oxidize divalent cobalt to trivalent cobalt to produce lithium cobaltate. Due to the poor gas permeability of the material layer, poor reaction kinetics and slow oxygen diffusion rate, oxidation sintering Long time and low production capacity. At the same time, the oxidation of cobalt in the material layer is incomplete or the oxidation in the material layer is uneven, and there is Co in the lithium cobalt oxide product 3 o 4 residues, affecting product quality; in addition, Co 3 o 4 Basically, cobalt salts and cobalt hydroxides are produced by high-temperature roasting. The process is long and the price is high, resulting in high raw material costs and small profit margins for the production of lithium cobalt oxide.

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