Regulating nucleation method during crystallization of nickel-cobalt-manganese precursor

Abstract

The invention discloses a regulating nucleation method during crystallization of a nickel-cobalt-manganese precursor. The method comprises the following steps: (1) adding a nickel-cobalt-manganese salt solution, an ammonia solution and an alkali solution into a closed reaction kettle containing a base liquid for a reaction; and (2) monitoring D50 and span values of particles generated in the reaction kettle; when the span value is smaller than 1, adding a nucleation feeding liquid to the reaction kettle, performing continuous stirring for the reaction, and monitoring the span value of the particles generated in the reaction kettle continuously; when the span value reaches a preset value, stopping adding the nucleation feeding liquid; and after the span value is lower than the preset value,adding the nucleation feeding liquid to the reaction kettle again, terminating the reaction until the D50 and span values of the particles generated in the reaction kettle reach a target particle size and the preset value separately, collecting materials, and then performing subsequent treatment so as to obtain the nickel-cobalt-manganese precursor, wherein the nucleation feeding liquid is a mixed solution of the nickel-cobalt-manganese salt solution and the ammonia solution, and span = (D90-D10) / D50.

Description

technical field [0001] The invention belongs to the field of lithium-ion battery materials, and in particular relates to a method for regulating nucleation during the crystallization process of a cathode material precursor. Background technique [0002] With the rapid development of digital electronic products and electric vehicles, the battery market has put forward higher requirements for the performance of lithium-ion batteries. The current commercialized lithium battery cathode materials include lithium cobaltate, lithium manganate, lithium iron phosphate, and nickel-cobalt lithium manganate. Due to the advantages of high discharge capacity and good cycle performance, lithium nickel cobalt manganese oxide has gradually increased its proportion in the application of positive electrode materials. With the increase of nickel content, the capacity per gram of lithium nickel cobalt manganese oxide will increase accordingly, so It has become the consensus of the lithium batte...

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Problems solved by technology

The above-mentioned patents all mentioned the use of multi-reactor series or parallel mode to solve the problem of particle size distribution in the precursor preparation process, but the multi-reactor series-parallel mode has insufficient equipment investment, and the process switching is complicated. The stability is poor, so it has not been widely promoted and applied in industrial production.

In the Chinese patent document CN102725232A, the single-pot mode is used, and the principle of process switching is used. Although the mode of nucleation first and then growth can avoid the disadvantages of the multi-pot series-parallel production mode, it can only be produced in a single-pot interval, and the production efficiency is low. Preparation of precursors with narrow particle size distribution, the particle size distribution cannot be adjusted

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