Coating technology of lithium cobalt oxide

Abstract

The invention relates to the technical field of lithium ion batteries, in particular to a coating technology of lithium cobalt oxide. The coating technology of the lithium cobalt oxide includes the following steps of weighting out a certain amount of lithium cobalt oxide, measuring metal ionic compounds and water-solubility organics based on the molar weight of the lithium cobalt oxide according to ratios that the total molar weight of the metal ionic compounds is 0.5%-2% of the molar weight of the lithium cobalt oxide and the total molar weight of the water-solubility organics is 50%-70% of the molar weight of the lithium cobalt oxide, adding water to the metal ionic compounds and the water-solubility organics, conducting ball-milling to obtain primary slurry, adding the lithium cobalt oxide and water to the primary slurry, conducting the ball-milling to obtain secondary slurry, drying the secondary slurry, roasting the secondary slurry, and obtaining coated lithium cobalt oxide materials. The coating technology of the lithium cobalt oxide is simple in technology process, low in cost, appropriate for industrialization large batch production, and capable of effectively avoiding the phenomenon that metallic elements generate segregation in the high-temperature process. In addition, the lithium cobalt oxide obtained through the coating technology is even in particle, less in agglomeration, good in electrochemical performance, and high in stability in charge-discharge processes.

Description

technical field [0001] The invention relates to the technical field of lithium ion batteries, in particular to a coating process of lithium cobalt oxide. Background technique [0002] Among the currently commercialized cathode materials for lithium-ion batteries, lithium cobalt oxide (LiCoO 2 ) Due to the relatively stable electrochemical performance, good cycle performance, high voltage platform, and good compatibility with the electrolyte, the compaction density of the positive electrode diaphragm can reach 4.1g / cm 3 , and does not affect battery performance, it is the most widely used and most mature cathode material. [0003] However, lithium cobalt oxide in lithium-ion batteries, when the charging voltage is above 4.3V, Li x The structure of CoO begins to deform, and the thermal stability becomes poor, resulting in poor cycle performance, while the product CoO, which is completely delithiated from lithium cobaltate 2 The structural stability is very poor, and it is e...

AI Technical Summary

Problems solved by technology

Its disadvantage is that, in order to ensure the uniformity of coating of the positive electrode material, the positive electrode material needs to be completely dissolved, the solvent usage is large, and the cost is high; The operation in production is difficult, and it is not suitable for mass production; in this method, when the hydrolyzed product M(OH)n is adsorbed on the surface of the active material, it is easy to cause excessive growth of the crystal grains of the active material, resulting in the particle size of the final active material being different. Uniformity affects its performance, and in this method, the positive electrode material is also directly roasted, which will also cause segregation of each component, and even lead to the precipitation of Li elements. Similarly, the roasting process of this method is a single roasting process. During the roasting process, the particles will burst due to violent drying, resulting in uneven particles, which will greatly affect the electrical properties and cycle performance of the coated positive electrode material

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