Preparation method of ternary positive electrode material precursor

Abstract

The invention provides a preparation method of a ternary positive electrode material precursor, wherein a reaction kettle, a circulating pump and a dynamic separation device which are sequentially communicated to form a suspension loop are utilized, so that the reaction efficiency and the product uniformity are effectively improved. The method comprises the following steps: preparing a metal salt mixed solution, a precipitant solution and a complexing agent solution, and adding the solutions into a reaction kettle in a parallel flow manner; controlling the reaction temperature in the reaction kettle to be 20-95 DEG C, the pH value to be 10-13 and the ammonia concentration to be 5-12g / L, and reacting; after the reaction kettle reaches a set liquid level, conveying the suspension liquid in the reaction kettle to a dynamic separation device through a circulating pump, carrying out solid-liquid separation, collecting separated mother liquor clear liquid to a mother liquor discharge tank, returning concentrated slurry to the reaction kettle for continuous reaction, and stopping feeding until solid materials in the reaction kettle meet specified physical and chemical characteristics; and unloading the materials to a finished product storage tank to enter a subsequent treatment process.

Description

technical field [0001] The invention belongs to the field of material preparation, and in particular relates to a preparation method of a battery ternary cathode material precursor. Background technique [0002] Lithium-ion batteries have the advantages of high working voltage, long cycle life, light weight, less self-discharge, no memory effect, and high cost performance. At present, they have been widely used in consumer electronics and new energy vehicles. Compared with lithium-ion batteries, sodium-ion batteries have relatively low energy density and voltage. They can be used in situations where there is no high requirement for volume and portability, and can give full play to the advantages of high sodium content and low cost. It has become a research topic. It is expected to become a cheap way to replace lithium-ion batteries. Among them, the cathode material is one of the core parts of the lithium / sodium ion battery, which determines the performance of the lithium / so...

AI Technical Summary

Problems solved by technology

The main problem in the existing preparation process is that the particle size distribution of the prepared precursor is not uniform and the average particle size is too small

[0004] Commonly used solid extractors have two forms: settling tank and thickener. Among them, the slurry cannot be concentrated to a higher solid content, generally not exceeding 20%, which limits the discharge flow rate of crystal nuclei; the thickener is filtered through a filter rod. To realize the solid-liquid separation of slurry, although the filtration area and efficiency are high, it is easy to form a filter cake, and the particles in the filter cake cannot fully contact with the saturated liquid, which affects the growth of particles during filtration and the overall particle uniformity of the reaction system In addition, the volume of the general thickener is relatively large, which makes the residence time of the solid material in the body longer, which also affects the reaction of the material and the uniformity of the product.

The separation of the external solid extractor increases the complexity of the process flow, operation and production cost, and the reaction efficiency is low

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