A preparing method of a spherical nickel cobalt lithium aluminate cathode material for lithium ion batteries

Abstract

The invention relates to a preparing method of a spherical nickel cobalt lithium aluminate cathode material for lithium ion batteries. The method mainly includes: by adopting an organic acid or salt complexing agent solution containing one or more -COO- group and free of ammonia nitrogen groups as a reaction base solution, a step of adding a soluble salt solution of nickel and cobalt and a meta-aluminate solution according to the needed mole ratio of nickel, cobalt and aluminum in the chemical formula of the nickel cobalt lithium aluminate cathode material together with an alkaline precipitant solution into the complexing agent solution, with the complexing agent being sufficiently excessive relative to the total mole of the nickel, the cobalt and the aluminum, the pH value of the reaction system being controlled to be 8-13 through an alkaline precipitant and the reaction temperature being controlled to be 30-90 DEG C; a step of filtering to obtain a spherical nickel cobalt lithium hydroxide precursor after the reaction is finished; a step of fully mixing with a lithium source and grinding; and a step of performing oxidizing roasting. The method is simple in process, environmental friendly, low in energy consumption, low in cost, stable and controllable in product performance and suitable for industrial production.

Description

technical field [0001] The invention relates to a preparation method of spherical nickel-cobalt-aluminate lithium, which is a positive electrode material of a lithium ion battery. Background technique [0002] Because of its high specific energy, long cycle life, low self-discharge rate and low environmental pollution, lithium-ion batteries have developed rapidly in the field of small power supplies and electric vehicle batteries. Lithium-ion batteries demanded by the market need to have higher energy density. [0003] LiNi 0.80 co 0.15 al 0.05 o 2 The cathode material has the advantages of low cost, high capacity, and good cycle stability, and it is considered to be one of the most attractive cathode materials currently. At present, domestic and foreign enterprises are already carrying out industrialization tests of such products. In recent years, the very popular Tesla electric vehicle is the application of this series of cathode materials. The application of this ma...

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Problems solved by technology

[0005] (1) In the two-stage method, it is difficult for aluminum to form a sufficiently uniform mixture with nickel and cobalt; and in the one-stage method, because the process is difficult to control and stabilize, Al 3+ If the nucleation speed is too fast, the spherical shape of the obtained precursor particles is poor, and the fluidity is not good;

[0006] (2) add a large amount of ammoniacal liquor as complexing agent in the preparation process, increased the cost of production;

[0007] (3) The added ammonia water will produce NH which is harmful to the environment during the production and preparation process 3 , and produce a large amount of ammonia nitrogen wastewater, which increases the difficulty of preparation and pollutes the environment

However, although this method solves the problem of nickel, cobalt and aluminum in the simultaneous precipitation of aluminum, it still does not solve a series of problems caused by the complexing agent ammonia

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