Preparation method of high-sphericity ternary precursor seed crystal and method for preparing high-sphericity ternary precursor by using seed crystal

Abstract

The invention relates to a preparation method of a high-sphericity ternary precursor seed crystal and a method for preparing a high-sphericity ternary precursor by using the seed crystal. According tothe preparation method of the high-sphericity ternary precursor seed crystal, the seed crystal with relatively good sphericity can be prepared, continuous production is realized, high-sphericity seedcrystals are continuously provided for precursor production, and the prepared high-sphericity seed crystals can be stored to be used as seed crystals for producing high-sphericity precursors in the next step and can also be independently used as small-particle-size precursors after being processed. According to the method for preparing the high-sphericity ternary precursor by using the seed crystal, the seed crystal grows up step by step by introducing the produced high-sphericity seed crystal and controlling the reaction conditions, so that the high-sphericity precursor meeting the requiredparticle size is obtained, and the production period is shortened.

Description

technical field [0001] The invention belongs to the technical field of precursors of ternary cathode materials for lithium ion batteries, in particular to a method for preparing a high-sphericity ternary precursor crystal seed and a method for preparing a high-sphericity ternary precursor by using the crystal seed. Background technique [0002] As a new type of green power source, lithium-ion batteries have been widely used in 3C digital electronic products, power tools, electric vehicles, energy storage and other fields. Ternary cathode materials are currently a hot spot that major companies are competing to develop, and ternary precursors have a crucial impact on the performance of cathode materials. [0003] Sphericity is one of the key dimensions for evaluating precursors. High sphericity can improve the tap density, rate performance, and cycle performance of cathode materials. Therefore, how to improve the sphericity of the precursor is an important technology. Accor...

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Problems solved by technology

[0005] Chinese patent CN104201367B discloses a high-density small particle size nickel-cobalt-manganese hydroxide and its preparation method, which adopts the complexation controlled crystallization co-precipitation method, through nucleation, growth, and continuous friction and collision of particles under continuously increasing solid-liquid ratio Under the special process flow, the nickel-cobalt-manganese soluble salt solution and the sodium hydroxide aqueous solution undergo a co-precipitation reaction under the complexation of ammonia to obtain a small particle size with uniform element distribution, good sphericity, uniform particle size distribution, and high tap density. Precipitation of nickel-cobalt-manganese hydroxide, which solves the problems of uneven element distribution, poor particle appearance, loose surface, difficult particle size control, unevenness and low tap density of the small particle size nickel-cobalt-manganese hydroxide prepared by the existing method

This method has agglomeration phenomenon when preparing precursors with small particle sizes, and although the sphericity has been improved, it still cannot meet the downstream customers' demand for high sphericity

[0006] Chinese patent CN107640792A and Chinese patent CN103253717B use the mother liquor with adjusted pH value and complexing agent content as the bottom liquid to synthesize small particles with good dispersibility. Although the sphericity has been greatly improved, there is still a significant agglomeration phenomenon. And the reunion at the beginning of the reaction is more serious

[0009] However, when customers are in urgent need of products, the production cycle of the products is relatively long, and it is difficult to obtain the required products in a short time, resulting in failure to deliver on time, or the products have been replaced after they are produced, and the value of the products is greatly reduced.

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