A method for regulating nucleation in the crystallization process of nickel-cobalt-manganese precursor

Abstract

A method for regulating nucleation during the crystallization process of a nickel-cobalt-manganese precursor, comprising the following steps: (1) adding nickel-cobalt-manganese salt solution, ammonia solution, and alkali solution into a closed reaction kettle equipped with a bottom liquid to react; (2) Monitor the D50 and span value of the particles generated in the reactor. When the span<1, add the nucleation feed liquid into the reactor to continue the stirring reaction. Continuously monitor the span value of the particles generated in the reactor. When the span value reaches the preset value , stop adding the nucleating feed liquid, when the span value is lower than the preset value, continue to add the nucleating feed liquid to the reactor until the D50 of the particles generated in the reactor reaches the target particle size and the span value reaches the preset value Finally, the reaction is completed, the material is collected and then subjected to subsequent processing to obtain a nickel-cobalt-manganese precursor; wherein, the nucleation feed solution is a mixed solution of nickel-cobalt-manganese salt solution and ammonia solution, 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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