Narrow-distribution small-particle-size nickel-cobalt-aluminum hydroxide and preparation method thereof

Abstract

A narrow-distribution small-particle-size nickel-cobalt-aluminum hydroxide serves as a precursor of a nickel-cobalt-lithium aluminate battery positive electrode material active substance, an inner core of secondary spherical particles of the precursor is aluminum hydroxide, a crystal grain cation layer framework of an outer shell layer contains nickel-cobalt-aluminum elements, and the mole percentof nickel is 85-98%; and secondary spherical particles of the precursor have the characteristic of narrow distribution, K90 is (D90-D10)/D50 and is less than or equal to 0.90, D50 is 2.0-6.0 [mu]m, and the energy density and the cycle performance of the battery can be further improved when the secondary spherical particles are used as a positive electrode material of the lithium battery. The invention discloses a preparation method of the narrow-distribution small-particle-size nickel-cobalt-aluminum hydroxide. On one hand, the defect that a precursor synthesized by a solid phase method cannot achieve atomic-level uniformity is overcome, and on the other hand, aluminum hydroxide flocculent precipitate generated in the synthesis process of a conventional liquid phase method is also overcome, so that the precursor with a core-shell structure, good sphericity, compact particles, stable structure and high consistency is obtained.

Description

technical field [0001] The invention belongs to the technical field of positive electrode material precursors for lithium ion batteries, in particular to a narrow-distributed small particle size nickel-cobalt-aluminum hydroxide and a preparation method thereof. Background technique [0002] Nickel-cobalt-aluminum ternary cathode material (NCA, that is, nickel-cobalt-aluminum oxide lithium) has high energy density and good rate performance, and is widely used in power tools, electric vehicles and other fields. [0003] At present, the preparation methods of nickel-cobalt-aluminum materials mainly include solid-phase synthesis and liquid-phase synthesis. Solid-phase synthesis generally uses co-precipitation to prepare nickel-cobalt precursors, which are then mixed with aluminum compounds and lithium source compounds for sintering. [0004] Chinese patent CN108767256A discloses a method for preparing a lithium nickel cobalt aluminate precursor of a battery positive electrode m...

AI Technical Summary

Problems solved by technology

This preparation method is the above-mentioned solid-phase method, and the mixing method cannot achieve uniformity at the atomic level, and the effect is not ideal

[0005] The liquid-phase synthesis method is to prepare the precursor of nickel-cobalt-aluminum by chemical co-precipitation method, and then calcined with lithium salt to obtain NCA material; since the solubility product constant of aluminum hydroxide is 1.3×10 -33 , while nickel hydroxide and cobalt hydroxide (divalent) are 2×10 -15 and 1.6×10 -15 , the solubility product constant ...

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