Precursor for ternary cathode material and preparation method thereof

Abstract

The invention provides a preparation method of a ternary cathode material precursor. The preparation method comprises the following steps: (1) co-precipitation: using pure water to prepare a mixed metal ion solution of soluble nickel salts, manganese salts, and cobalt salts, mixing the mixed metal ion solution with an alkali metal hydroxide solution and an ammonium salt solution; after precipitation, separating solids and liquid, and blowing the solids to obtain a first nickel-manganese-cobalt hydroxide material; and (2) primary drying: drying the first nickel-manganese-cobalt hydroxide material obtained in the step (1) in vacuum to obtain the primarily dried ternary cathode material precursor. The ternary cathode material precursor prepared by the provided preparation method has the following physical and chemical indexes: the particle distribution span is not more than 1.2; D50 is 9 to 12 [mu]m; and the tap density is not less than 2.40 g / cm3. The preparation method has the advantages that the operation is simple, the particle distribution of prepared ternary cathode material precursor is uniform, the tap density is high, impurities can be removed easily, and the method is practical.

Description

technical field [0001] The invention belongs to the field of positive electrode materials for lithium ion batteries, and in particular relates to a precursor for ternary positive electrode materials and a preparation method thereof. Background technique [0002] Lithium-ion batteries have been widely used in many fields due to their excellent performance such as high voltage, high capacity, low consumption, no memory effect, small size, low internal resistance, low self-discharge and many cycles. In particular, ternary materials have the advantages of high specific capacity, long cycle life, good safety performance and low price, but low first effect and low charge and discharge platform are also the main shortcomings of ternary materials. At present, most manufacturers only improve the sintering process, improve the performance of the material through coating and doping, and invest less in the improvement of the precursor. However, the quality of the precursor plays a cruci...

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Problems solved by technology

[0003] 1. The washing process cannot completely remove the entrapped Na + and SO 4 2- Impurities such as ions are washed and removed, the sodium content is about 200ppm, and the S content is 600-1500ppm

[0004] 2. The particle size distribution of the continuous synthesis precursor is uneven, and the diameter distance is relatively large, generally 1.2-1.8, which affects the mixing uniformity with lithium in the later mixing process

[0005] 3. The hydroxide precursor synthesized by the general process not only has a small tap density, but also has a great influence on the pH of the sintered product and the various properties of the lithium-ion battery

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