Method for synthesizing wide-particle-size-distribution nickel-cobalt-aluminum positive electrode material precursor through continuous coprecipitation

Abstract

The invention discloses a method for synthesizing a wide-particle-size-distribution nickel-cobalt-aluminum positive electrode material precursor through continuous coprecipitation. Through coprecipitation in a reactor, spherical nickel cobalt aluminum hydroxide powder with wide particle size distribution is synthesized. In the synthesis process, two stages of starting kettle reaction for constructing particle size gradient and maintaining particle size stability are carried out separately, process parameter control is carried out according to different pH value process conditions; overflow liquid is subjected to synthesis treatment for eliminating micro powder, so that the nickel cobalt aluminum hydroxide powder with wide particle size distribution is obtain; and after solid-liquid separation, residues in the powder are removed in a reinforced washing mode, dispersity of the powder is guaranteed, and after full drying, a nickel-cobalt-aluminum positive electrode material precursor withan adjustable average particle size D50 in a range of 10-15 [mu]m and a tap density of 2.0 g/cm<3> or above is prepared. The preparation method is simple in technological process and suitable for industrial large-scale production of the nickel-cobalt-aluminum positive electrode material precursor.

Description

technical field [0001] The invention relates to a method for preparing a hydroxide precursor material for a lithium-ion battery positive electrode material, in particular to a method for preparing a hydroxide precursor material with a wide particle size distribution for a nickel-cobalt-aluminum positive electrode material in a lithium-ion power battery. Background technique [0002] Due to the advantages of high energy density, good cycle performance, and environmental protection, lithium-ion batteries are widely used in various mobile electronic products, and will be increasingly used in the field of electric vehicles. Cathode material occupies the most important position in the product composition of lithium-ion batteries. The quality of the cathode material directly determines the final performance of the battery, and the proportion of the cathode material in the battery cost is as high as 40%. [0003] Under the situation that the mileage requirements of new energy vehic...

AI Technical Summary

Problems solved by technology

The solid-phase mixing method generally mixes aluminum hydroxide powder into nickel-cobalt hydroxide powder by mechanical mixing. The process is simple and low-cost, but aluminum cannot be mixed uniformly in nickel-cobalt, resulting in poor electrochemical performance of the product; co-precipitation The technological process of the method is relatively simple, but due to Al 3+ 、Ni 2+ and Co 2+ The Ksp of the three ions are 1.9×10 -33 , 2×10 -15 and 1.6×10 -15 Too much difference, Al 3+ it's hard to be with you 2+ 、Co 2+ Homogeneous co-precipitation is achieved, and the lattice order of the precursor becomes poor

However, different preparation methods have their own advantages, such as low reaction temperature, uniform mixing of raw materials, good reproducibility and consistency of material preparation, easy control of chemical reaction progress, etc., and can synthesize positive electrode materials with good layered structure. But they also have corresponding disadvantages, therefore, existing preparation methods all need to continue to study and improve

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