Preparation method and device of nickel-cobalt-aluminum anode material precursor

Abstract

The invention discloses a preparation method and a preparation device of a nickel-cobalt-aluminum anode material precursor. The preparation method is characterized by comprising the following steps: preparing a nickel-cobalt-aluminum mixed salt solution containing a complexing agent and a strong base solution containing ammonia water; combining the nickel-cobalt-aluminum mixed salt solution with the strong base solution at a uniform flowing speed and synchronously filling into a reaction kettle with a base solution for co-precipitation reaction; after the nickel-cobalt-aluminum mixed salt solution is filled, stopping adding the strong base solution, and after the reaction is completed, aging the slurry, and further performing liquid-solid separation, thereby obtaining the nickel-cobalt-aluminum anode material precursor. According to the preparation method and the device, the complexing agent is directly added into an aluminum solution, and the complexing agent is complexed with aluminum ions before the co-precipitation reaction, so that aluminum can be prevented from nucleating and precipitating immediately after entering the reaction system; meanwhile, a mixed salt solution is prepared from nickel, cobalt and aluminum together, so that the ratio of nickel and cobalt to aluminum in the formed precursor is accordant with that of an expected nickel-cobalt-lithium aluminate material at any moment, nickel, cobalt and aluminum can be subjected to uniform co-precipitation reaction, and the nickel-cobalt-aluminum anode material precursor of which indexes such as the morphology, the granularity and the density are all higher than those of similar products can be prepared.

Description

technical field [0001] The invention relates to the technical field of cathode materials for lithium ion batteries, in particular to a preparation method and device for a nickel-cobalt-aluminum cathode material precursor. Background technique [0002] Nickel-cobalt-aluminum ternary cathode material (NCA, that is, nickel-cobalt-aluminate lithium) has the advantages of high specific capacity, high voltage and good cycle performance, and has attracted extensive attention in recent years. The NCA material belongs to the aluminum-doped nickel-cobalt series cathode materials, and the representative material in the nickel-cobalt series cathode materials is LiNi 0.8 co 0.2 o 2 Compared with the same series of materials, the positive electrode material of this composition has better energy density, but has disadvantages such as poor overcharge resistance, poor thermal stability, and high irreversible capacity for the first discharge. LiNi 0.8 co 0.2 o 2 Adding Al element to the...

AI Technical Summary

Problems solved by technology

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 Therefore, when the nickel-cobalt-aluminum precursor is prepared by the chemical co-precipitation method, the precipitation of trivalent aluminum ions is particularly fast, not only difficult to form a uniform single layered structure with nickel and cobalt precipitation, but also difficult to form spherical large particle precipitation, so the precursor The performance index of NCA material obtained by calcining bulk doped lithium salt is not ideal

Images